Add API channges between 3.6 and 3.7

Most API changes are introduced due to the migration from gogo/protobuf to standard protobuf

Raft side API chanages

Compare go.etcd.io/raft/v3 between 3.6 and 3.7

```
Incompatible changes:
- (*MemoryStorage).Append: changed from func([]go.etcd.io/raft/v3/raftpb.Entry) error to func([]*go.etcd.io/raft/v3/raftpb.Entry) error
- (*MemoryStorage).ApplySnapshot: changed from func(go.etcd.io/raft/v3/raftpb.Snapshot) error to func(*go.etcd.io/raft/v3/raftpb.Snapshot) error
- (*MemoryStorage).CreateSnapshot: changed from func(uint64, *go.etcd.io/raft/v3/raftpb.ConfState, []byte) (go.etcd.io/raft/v3/raftpb.Snapshot, error) to func(uint64, *go.etcd.io/raft/v3/raftpb.ConfState, []byte) (*go.etcd.io/raft/v3/raftpb.Snapshot, error)
- (*MemoryStorage).Entries: changed from func(uint64, uint64, uint64) ([]go.etcd.io/raft/v3/raftpb.Entry, error) to func(uint64, uint64, uint64) ([]*go.etcd.io/raft/v3/raftpb.Entry, error)
- (*MemoryStorage).InitialState: changed from func() (go.etcd.io/raft/v3/raftpb.HardState, go.etcd.io/raft/v3/raftpb.ConfState, error) to func() (*go.etcd.io/raft/v3/raftpb.HardState, *go.etcd.io/raft/v3/raftpb.ConfState, error)
- (*MemoryStorage).SetHardState: changed from func(go.etcd.io/raft/v3/raftpb.HardState) error to func(*go.etcd.io/raft/v3/raftpb.HardState) error
- (*MemoryStorage).Snapshot: changed from func() (go.etcd.io/raft/v3/raftpb.Snapshot, error) to func() (*go.etcd.io/raft/v3/raftpb.Snapshot, error)
- (*RawNode).Step: changed from func(go.etcd.io/raft/v3/raftpb.Message) error to func(*go.etcd.io/raft/v3/raftpb.Message) error
- ./raftpb.(*HardState).Marshal, method set of *BasicStatus: removed
- ./raftpb.(*HardState).Marshal, method set of *Ready: removed
- ./raftpb.(*HardState).Marshal, method set of *Status: removed
- ./raftpb.(*HardState).MarshalTo, method set of *BasicStatus: removed
- ./raftpb.(*HardState).MarshalTo, method set of *Ready: removed
- ./raftpb.(*HardState).MarshalTo, method set of *Status: removed
- ./raftpb.(*HardState).MarshalToSizedBuffer, method set of *BasicStatus: removed
- ./raftpb.(*HardState).MarshalToSizedBuffer, method set of *Ready: removed
- ./raftpb.(*HardState).MarshalToSizedBuffer, method set of *Status: removed
- ./raftpb.(*HardState).Size, method set of *BasicStatus: removed
- ./raftpb.(*HardState).Size, method set of *Ready: removed
- ./raftpb.(*HardState).Size, method set of *Status: removed
- ./raftpb.(*HardState).Unmarshal, method set of *BasicStatus: removed
- ./raftpb.(*HardState).Unmarshal, method set of *Ready: removed
- ./raftpb.(*HardState).Unmarshal, method set of *Status: removed
- ./raftpb.(*HardState).XXX_DiscardUnknown, method set of *BasicStatus: removed
- ./raftpb.(*HardState).XXX_DiscardUnknown, method set of *Ready: removed
- ./raftpb.(*HardState).XXX_DiscardUnknown, method set of *Status: removed
- ./raftpb.(*HardState).XXX_Marshal, method set of *BasicStatus: removed
- ./raftpb.(*HardState).XXX_Marshal, method set of *Ready: removed
- ./raftpb.(*HardState).XXX_Marshal, method set of *Status: removed
- ./raftpb.(*HardState).XXX_Merge, method set of *BasicStatus: removed
- ./raftpb.(*HardState).XXX_Merge, method set of *Ready: removed
- ./raftpb.(*HardState).XXX_Merge, method set of *Status: removed
- ./raftpb.(*HardState).XXX_Size, method set of *BasicStatus: removed
- ./raftpb.(*HardState).XXX_Size, method set of *Ready: removed
- ./raftpb.(*HardState).XXX_Size, method set of *Status: removed
- ./raftpb.(*HardState).XXX_Unmarshal, method set of *BasicStatus: removed
- ./raftpb.(*HardState).XXX_Unmarshal, method set of *Ready: removed
- ./raftpb.(*HardState).XXX_Unmarshal, method set of *Status: removed
- BasicStatus.Commit: changed from uint64 to *uint64
- BasicStatus.HardState: changed from go.etcd.io/raft/v3/raftpb.HardState to *go.etcd.io/raft/v3/raftpb.HardState
- BasicStatus.Term: changed from uint64 to *uint64
- BasicStatus.Vote: changed from uint64 to *uint64
- DescribeConfState: changed from func(go.etcd.io/raft/v3/raftpb.ConfState) string to func(*go.etcd.io/raft/v3/raftpb.ConfState) string
- DescribeEntries: changed from func([]go.etcd.io/raft/v3/raftpb.Entry, EntryFormatter) string to func([]*go.etcd.io/raft/v3/raftpb.Entry, EntryFormatter) string
- DescribeEntry: changed from func(go.etcd.io/raft/v3/raftpb.Entry, EntryFormatter) string to func(*go.etcd.io/raft/v3/raftpb.Entry, EntryFormatter) string
- DescribeHardState: changed from func(go.etcd.io/raft/v3/raftpb.HardState) string to func(*go.etcd.io/raft/v3/raftpb.HardState) string
- DescribeMessage: changed from func(go.etcd.io/raft/v3/raftpb.Message, EntryFormatter) string to func(*go.etcd.io/raft/v3/raftpb.Message, EntryFormatter) string
- DescribeSnapshot: changed from func(go.etcd.io/raft/v3/raftpb.Snapshot) string to func(*go.etcd.io/raft/v3/raftpb.Snapshot) string
- IsEmptyHardState: changed from func(go.etcd.io/raft/v3/raftpb.HardState) bool to func(*go.etcd.io/raft/v3/raftpb.HardState) bool
- IsEmptySnap: changed from func(go.etcd.io/raft/v3/raftpb.Snapshot) bool to func(*go.etcd.io/raft/v3/raftpb.Snapshot) bool
- MustSync: changed from func(go.etcd.io/raft/v3/raftpb.HardState, go.etcd.io/raft/v3/raftpb.HardState, int) bool to func(*go.etcd.io/raft/v3/raftpb.HardState, *go.etcd.io/raft/v3/raftpb.HardState, int) bool
- Node.Step: changed from func(context.Context, go.etcd.io/raft/v3/raftpb.Message) error to func(context.Context, *go.etcd.io/raft/v3/raftpb.Message) error
- Ready.Commit: changed from uint64 to *uint64
- Ready.CommittedEntries: changed from []go.etcd.io/raft/v3/raftpb.Entry to []*go.etcd.io/raft/v3/raftpb.Entry
- Ready.Entries: changed from []go.etcd.io/raft/v3/raftpb.Entry to []*go.etcd.io/raft/v3/raftpb.Entry
- Ready.HardState: changed from go.etcd.io/raft/v3/raftpb.HardState to *go.etcd.io/raft/v3/raftpb.HardState
- Ready.Messages: changed from []go.etcd.io/raft/v3/raftpb.Message to []*go.etcd.io/raft/v3/raftpb.Message
- Ready.Snapshot: changed from go.etcd.io/raft/v3/raftpb.Snapshot to *go.etcd.io/raft/v3/raftpb.Snapshot
- Ready.Term: changed from uint64 to *uint64
- Ready.Vote: changed from uint64 to *uint64
- Status.Commit: changed from uint64 to *uint64
- Status.HardState: changed from go.etcd.io/raft/v3/raftpb.HardState to *go.etcd.io/raft/v3/raftpb.HardState
- Status.Term: changed from uint64 to *uint64
- Status.Vote: changed from uint64 to *uint64
- Storage.Entries: changed from func(uint64, uint64, uint64) ([]go.etcd.io/raft/v3/raftpb.Entry, error) to func(uint64, uint64, uint64) ([]*go.etcd.io/raft/v3/raftpb.Entry, error)
- Storage.InitialState: changed from func() (go.etcd.io/raft/v3/raftpb.HardState, go.etcd.io/raft/v3/raftpb.ConfState, error) to func() (*go.etcd.io/raft/v3/raftpb.HardState, *go.etcd.io/raft/v3/raftpb.ConfState, error)
- Storage.Snapshot: changed from func() (go.etcd.io/raft/v3/raftpb.Snapshot, error) to func() (*go.etcd.io/raft/v3/raftpb.Snapshot, error)
- (*RawNode).Step: changed from func(go.etcd.io/raft/v3/raftpb.Message) error to func(*go.etcd.io/raft/v3/raftpb.Message) error
- ./rafttest.(*InteractionEnv).AddNodes: changed from func(int, go.etcd.io/raft/v3.Config, go.etcd.io/raft/v3/raftpb.Snapshot) error to func(int, go.etcd.io/raft/v3.Config, *go.etcd.io/raft/v3/raftpb.Snapshot) error
- ./rafttest.InteractionEnv.Messages: changed from []go.etcd.io/raft/v3/raftpb.Message to []*go.etcd.io/raft/v3/raftpb.Message
- ./rafttest.Node.AppendWork: changed from []go.etcd.io/raft/v3/raftpb.Message to []*go.etcd.io/raft/v3/raftpb.Message
- ./rafttest.Node.ApplyWork: changed from []go.etcd.io/raft/v3/raftpb.Message to []*go.etcd.io/raft/v3/raftpb.Message
- ./rafttest.Node.History: changed from []go.etcd.io/raft/v3/raftpb.Snapshot to []*go.etcd.io/raft/v3/raftpb.Snapshot
- ./rafttest.Storage.Append: changed from func([]go.etcd.io/raft/v3/raftpb.Entry) error to func([]*go.etcd.io/raft/v3/raftpb.Entry) error
- ./rafttest.Storage.ApplySnapshot: changed from func(go.etcd.io/raft/v3/raftpb.Snapshot) error to func(*go.etcd.io/raft/v3/raftpb.Snapshot) error
- ./rafttest.Storage.SetHardState: changed from func(go.etcd.io/raft/v3/raftpb.HardState) error to func(*go.etcd.io/raft/v3/raftpb.HardState) error
- Storage.Entries: changed from func(uint64, uint64, uint64) ([]go.etcd.io/raft/v3/raftpb.Entry, error) to func(uint64, uint64, uint64) ([]*go.etcd.io/raft/v3/raftpb.Entry, error)
- Storage.InitialState: changed from func() (go.etcd.io/raft/v3/raftpb.HardState, go.etcd.io/raft/v3/raftpb.ConfState, error) to func() (*go.etcd.io/raft/v3/raftpb.HardState, *go.etcd.io/raft/v3/raftpb.ConfState, error)
- Storage.Snapshot: changed from func() (go.etcd.io/raft/v3/raftpb.Snapshot, error) to func() (*go.etcd.io/raft/v3/raftpb.Snapshot, error)
- ./raftpb.(*ConfChange).AsV1: changed from func() (ConfChange, bool) to func() (*ConfChange, bool)
- ./raftpb.(*ConfChange).AsV2: changed from func() ConfChangeV2 to func() *ConfChangeV2
- ./raftpb.(*ConfChange).Marshal: removed
- ./raftpb.(*ConfChange).MarshalTo: removed
- ./raftpb.(*ConfChange).MarshalToSizedBuffer: removed
- ./raftpb.(*ConfChange).Size: removed
- ./raftpb.(*ConfChange).Unmarshal: removed
- ./raftpb.(*ConfChange).XXX_DiscardUnknown: removed
- ./raftpb.(*ConfChange).XXX_Marshal: removed
- ./raftpb.(*ConfChange).XXX_Merge: removed
- ./raftpb.(*ConfChange).XXX_Size: removed
- ./raftpb.(*ConfChange).XXX_Unmarshal: removed
- ./raftpb.(*ConfChangeSingle).Marshal: removed
- ./raftpb.(*ConfChangeSingle).MarshalTo: removed
- ./raftpb.(*ConfChangeSingle).MarshalToSizedBuffer: removed
- ./raftpb.(*ConfChangeSingle).Size: removed
- ./raftpb.(*ConfChangeSingle).Unmarshal: removed
- ./raftpb.(*ConfChangeSingle).XXX_DiscardUnknown: removed
- ./raftpb.(*ConfChangeSingle).XXX_Marshal: removed
- ./raftpb.(*ConfChangeSingle).XXX_Merge: removed
- ./raftpb.(*ConfChangeSingle).XXX_Size: removed
- ./raftpb.(*ConfChangeSingle).XXX_Unmarshal: removed
- ./raftpb.(*ConfChangeV2).AsV1: changed from func() (ConfChange, bool) to func() (*ConfChange, bool)
- ./raftpb.(*ConfChangeV2).AsV2: changed from func() ConfChangeV2 to func() *ConfChangeV2
- ./raftpb.(*ConfChangeV2).Marshal: removed
- ./raftpb.(*ConfChangeV2).MarshalTo: removed
- ./raftpb.(*ConfChangeV2).MarshalToSizedBuffer: removed
- ./raftpb.(*ConfChangeV2).Size: removed
- ./raftpb.(*ConfChangeV2).Unmarshal: removed
- ./raftpb.(*ConfChangeV2).XXX_DiscardUnknown: removed
- ./raftpb.(*ConfChangeV2).XXX_Marshal: removed
- ./raftpb.(*ConfChangeV2).XXX_Merge: removed
- ./raftpb.(*ConfChangeV2).XXX_Size: removed
- ./raftpb.(*ConfChangeV2).XXX_Unmarshal: removed
- ./raftpb.(*ConfState).Equivalent: changed from func(ConfState) error to func(*ConfState) error
- ./raftpb.(*ConfState).Marshal: removed
- ./raftpb.(*ConfState).MarshalTo: removed
- ./raftpb.(*ConfState).MarshalToSizedBuffer: removed
- ./raftpb.(*ConfState).Size: removed
- ./raftpb.(*ConfState).Unmarshal: removed
- ./raftpb.(*ConfState).XXX_DiscardUnknown: removed
- ./raftpb.(*ConfState).XXX_Marshal: removed
- ./raftpb.(*ConfState).XXX_Merge: removed
- ./raftpb.(*ConfState).XXX_Size: removed
- ./raftpb.(*ConfState).XXX_Unmarshal: removed
- ./raftpb.(*Entry).Marshal: removed
- ./raftpb.(*Entry).MarshalTo: removed
- ./raftpb.(*Entry).MarshalToSizedBuffer: removed
- ./raftpb.(*Entry).Size: removed
- ./raftpb.(*Entry).Unmarshal: removed
- ./raftpb.(*Entry).XXX_DiscardUnknown: removed
- ./raftpb.(*Entry).XXX_Marshal: removed
- ./raftpb.(*Entry).XXX_Merge: removed
- ./raftpb.(*Entry).XXX_Size: removed
- ./raftpb.(*Entry).XXX_Unmarshal: removed
- ./raftpb.(*HardState).Marshal: removed
- ./raftpb.(*HardState).MarshalTo: removed
- ./raftpb.(*HardState).MarshalToSizedBuffer: removed
- ./raftpb.(*HardState).Size: removed
- ./raftpb.(*HardState).Unmarshal: removed
- ./raftpb.(*HardState).XXX_DiscardUnknown: removed
- ./raftpb.(*HardState).XXX_Marshal: removed
- ./raftpb.(*HardState).XXX_Merge: removed
- ./raftpb.(*HardState).XXX_Size: removed
- ./raftpb.(*HardState).XXX_Unmarshal: removed
- ./raftpb.(*Message).Marshal: removed
- ./raftpb.(*Message).MarshalTo: removed
- ./raftpb.(*Message).MarshalToSizedBuffer: removed
- ./raftpb.(*Message).Size: removed
- ./raftpb.(*Message).Unmarshal: removed
- ./raftpb.(*Message).XXX_DiscardUnknown: removed
- ./raftpb.(*Message).XXX_Marshal: removed
- ./raftpb.(*Message).XXX_Merge: removed
- ./raftpb.(*Message).XXX_Size: removed
- ./raftpb.(*Message).XXX_Unmarshal: removed
- ./raftpb.(*Snapshot).Marshal: removed
- ./raftpb.(*Snapshot).MarshalTo: removed
- ./raftpb.(*Snapshot).MarshalToSizedBuffer: removed
- ./raftpb.(*Snapshot).Size: removed
- ./raftpb.(*Snapshot).Unmarshal: removed
- ./raftpb.(*Snapshot).XXX_DiscardUnknown: removed
- ./raftpb.(*Snapshot).XXX_Marshal: removed
- ./raftpb.(*Snapshot).XXX_Merge: removed
- ./raftpb.(*Snapshot).XXX_Size: removed
- ./raftpb.(*Snapshot).XXX_Unmarshal: removed
- ./raftpb.(*SnapshotMetadata).Marshal: removed
- ./raftpb.(*SnapshotMetadata).MarshalTo: removed
- ./raftpb.(*SnapshotMetadata).MarshalToSizedBuffer: removed
- ./raftpb.(*SnapshotMetadata).Size: removed
- ./raftpb.(*SnapshotMetadata).Unmarshal: removed
- ./raftpb.(*SnapshotMetadata).XXX_DiscardUnknown: removed
- ./raftpb.(*SnapshotMetadata).XXX_Marshal: removed
- ./raftpb.(*SnapshotMetadata).XXX_Merge: removed
- ./raftpb.(*SnapshotMetadata).XXX_Size: removed
- ./raftpb.(*SnapshotMetadata).XXX_Unmarshal: removed
- ./raftpb.ConfChange.AsV1: removed
- ./raftpb.ConfChange.AsV2: removed
- ./raftpb.ConfChange.ID: removed
- ./raftpb.ConfChange.NodeID: removed
- ./raftpb.ConfChange.Type: changed from ConfChangeType to *ConfChangeType
- ./raftpb.ConfChange: no longer implements ./raftpb.ConfChangeI
- ./raftpb.ConfChangeI.AsV1: changed from func() (ConfChange, bool) to func() (*ConfChange, bool)
- ./raftpb.ConfChangeI.AsV2: changed from func() ConfChangeV2 to func() *ConfChangeV2
- ./raftpb.ConfChangeSingle.NodeID: removed
- ./raftpb.ConfChangeSingle.Type: changed from ConfChangeType to *ConfChangeType
- ./raftpb.ConfChangeSingle: old is comparable, new is not
- ./raftpb.ConfChangeV2.AsV1: removed
- ./raftpb.ConfChangeV2.AsV2: removed
- ./raftpb.ConfChangeV2.Changes: changed from []ConfChangeSingle to []*ConfChangeSingle
- ./raftpb.ConfChangeV2.EnterJoint: removed
- ./raftpb.ConfChangeV2.LeaveJoint: removed
- ./raftpb.ConfChangeV2.Transition: changed from ConfChangeTransition to *ConfChangeTransition
- ./raftpb.ConfChangeV2: no longer implements ./raftpb.ConfChangeI
- ./raftpb.ConfChangesFromString: changed from func(string) ([]ConfChangeSingle, error) to func(string) ([]*ConfChangeSingle, error)
- ./raftpb.ConfChangesToString: changed from func([]ConfChangeSingle) string to func([]*ConfChangeSingle) string
- ./raftpb.ConfState.AutoLeave: changed from bool to *bool
- ./raftpb.ConfState.Equivalent: removed
- ./raftpb.Entry.Index: changed from uint64 to *uint64
- ./raftpb.Entry.Term: changed from uint64 to *uint64
- ./raftpb.Entry.Type: changed from EntryType to *EntryType
- ./raftpb.ErrIntOverflowRaft: removed
- ./raftpb.ErrInvalidLengthRaft: removed
- ./raftpb.ErrUnexpectedEndOfGroupRaft: removed
- ./raftpb.HardState.Commit: changed from uint64 to *uint64
- ./raftpb.HardState.Term: changed from uint64 to *uint64
- ./raftpb.HardState.Vote: changed from uint64 to *uint64
- ./raftpb.HardState: old is comparable, new is not
- ./raftpb.Message.Commit: changed from uint64 to *uint64
- ./raftpb.Message.Entries: changed from []Entry to []*Entry
- ./raftpb.Message.From: changed from uint64 to *uint64
- ./raftpb.Message.Index: changed from uint64 to *uint64
- ./raftpb.Message.LogTerm: changed from uint64 to *uint64
- ./raftpb.Message.Reject: changed from bool to *bool
- ./raftpb.Message.RejectHint: changed from uint64 to *uint64
- ./raftpb.Message.Responses: changed from []Message to []*Message
- ./raftpb.Message.Term: changed from uint64 to *uint64
- ./raftpb.Message.To: changed from uint64 to *uint64
- ./raftpb.Message.Type: changed from MessageType to *MessageType
- ./raftpb.Message.Vote: changed from uint64 to *uint64
- ./raftpb.Snapshot.Metadata: changed from SnapshotMetadata to *SnapshotMetadata
- ./raftpb.SnapshotMetadata.ConfState: changed from ConfState to *ConfState
- ./raftpb.SnapshotMetadata.Index: changed from uint64 to *uint64
- ./raftpb.SnapshotMetadata.Term: changed from uint64 to *uint64
- ./tracker.(*ProgressTracker).ConfState: changed from func() go.etcd.io/raft/v3/raftpb.ConfState to func() *go.etcd.io/raft/v3/raftpb.ConfState
- ./confchange.Changer.EnterJoint: changed from func(bool, ...go.etcd.io/raft/v3/raftpb.ConfChangeSingle) (go.etcd.io/raft/v3/tracker.Config, go.etcd.io/raft/v3/tracker.ProgressMap, error) to func(bool, ...*go.etcd.io/raft/v3/raftpb.ConfChangeSingle) (go.etcd.io/raft/v3/tracker.Config, go.etcd.io/raft/v3/tracker.ProgressMap, error)
- ./confchange.Changer.Simple: changed from func(...go.etcd.io/raft/v3/raftpb.ConfChangeSingle) (go.etcd.io/raft/v3/tracker.Config, go.etcd.io/raft/v3/tracker.ProgressMap, error) to func(...*go.etcd.io/raft/v3/raftpb.ConfChangeSingle) (go.etcd.io/raft/v3/tracker.Config, go.etcd.io/raft/v3/tracker.ProgressMap, error)
- ./confchange.Describe: changed from func(...go.etcd.io/raft/v3/raftpb.ConfChangeSingle) string to func(...*go.etcd.io/raft/v3/raftpb.ConfChangeSingle) string
- ./confchange.Restore: changed from func(Changer, go.etcd.io/raft/v3/raftpb.ConfState) (go.etcd.io/raft/v3/tracker.Config, go.etcd.io/raft/v3/tracker.ProgressMap, error) to func(Changer, *go.etcd.io/raft/v3/raftpb.ConfState) (go.etcd.io/raft/v3/tracker.Config, go.etcd.io/raft/v3/tracker.ProgressMap, error)
Compatible changes:
- ./raftpb.(*HardState).Descriptor: added
- ./raftpb.(*HardState).GetCommit: added
- ./raftpb.(*HardState).GetTerm: added
- ./raftpb.(*HardState).GetVote: added
- ./raftpb.(*HardState).ProtoMessage: added
- ./raftpb.(*HardState).ProtoReflect: added
- ./raftpb.(*HardState).Reset: added
- ./raftpb.(*HardState).String: added
- DescribeConfChange: added
- ./raftpb.(*ConfChange).GetContext: added
- ./raftpb.(*ConfChange).GetId: added
- ./raftpb.(*ConfChange).GetNodeId: added
- ./raftpb.(*ConfChange).GetType: added
- ./raftpb.(*ConfChange).ProtoReflect: added
- ./raftpb.(*ConfChangeSingle).GetNodeId: added
- ./raftpb.(*ConfChangeSingle).GetType: added
- ./raftpb.(*ConfChangeSingle).ProtoReflect: added
- ./raftpb.(*ConfChangeV2).GetChanges: added
- ./raftpb.(*ConfChangeV2).GetContext: added
- ./raftpb.(*ConfChangeV2).GetTransition: added
- ./raftpb.(*ConfChangeV2).ProtoReflect: added
- ./raftpb.(*ConfState).GetAutoLeave: added
- ./raftpb.(*ConfState).GetLearners: added
- ./raftpb.(*ConfState).GetLearnersNext: added
- ./raftpb.(*ConfState).GetVoters: added
- ./raftpb.(*ConfState).GetVotersOutgoing: added
- ./raftpb.(*ConfState).ProtoReflect: added
- ./raftpb.(*Entry).GetData: added
- ./raftpb.(*Entry).GetIndex: added
- ./raftpb.(*Entry).GetTerm: added
- ./raftpb.(*Entry).GetType: added
- ./raftpb.(*Entry).ProtoReflect: added
- ./raftpb.(*HardState).GetCommit: added
- ./raftpb.(*HardState).GetTerm: added
- ./raftpb.(*HardState).GetVote: added
- ./raftpb.(*HardState).ProtoReflect: added
- ./raftpb.(*Message).GetCommit: added
- ./raftpb.(*Message).GetContext: added
- ./raftpb.(*Message).GetEntries: added
- ./raftpb.(*Message).GetFrom: added
- ./raftpb.(*Message).GetIndex: added
- ./raftpb.(*Message).GetLogTerm: added
- ./raftpb.(*Message).GetReject: added
- ./raftpb.(*Message).GetRejectHint: added
- ./raftpb.(*Message).GetResponses: added
- ./raftpb.(*Message).GetSnapshot: added
- ./raftpb.(*Message).GetTerm: added
- ./raftpb.(*Message).GetTo: added
- ./raftpb.(*Message).GetType: added
- ./raftpb.(*Message).GetVote: added
- ./raftpb.(*Message).ProtoReflect: added
- ./raftpb.(*Snapshot).GetData: added
- ./raftpb.(*Snapshot).GetMetadata: added
- ./raftpb.(*Snapshot).ProtoReflect: added
- ./raftpb.(*SnapshotMetadata).GetConfState: added
- ./raftpb.(*SnapshotMetadata).GetIndex: added
- ./raftpb.(*SnapshotMetadata).GetTerm: added
- ./raftpb.(*SnapshotMetadata).ProtoReflect: added
- ./raftpb.ConfChange.Id: added
- ./raftpb.ConfChange.NodeId: added
- ./raftpb.ConfChangeSingle.NodeId: added
- ./raftpb.ConfChangeTransition.Descriptor: added
- ./raftpb.ConfChangeTransition.Number: added
- ./raftpb.ConfChangeTransition.Type: added
- ./raftpb.ConfChangeTransition_ConfChangeTransitionAuto: added
- ./raftpb.ConfChangeTransition_ConfChangeTransitionJointExplicit: added
- ./raftpb.ConfChangeTransition_ConfChangeTransitionJointImplicit: added
- ./raftpb.ConfChangeType.Descriptor: added
- ./raftpb.ConfChangeType.Number: added
- ./raftpb.ConfChangeType.Type: added
- ./raftpb.ConfChangeType_ConfChangeAddLearnerNode: added
- ./raftpb.ConfChangeType_ConfChangeAddNode: added
- ./raftpb.ConfChangeType_ConfChangeRemoveNode: added
- ./raftpb.ConfChangeType_ConfChangeUpdateNode: added
- ./raftpb.EnsureConfState: added
- ./raftpb.EnsureSnapshot: added
- ./raftpb.EnsureSnapshotMetadata: added
- ./raftpb.EntryType.Descriptor: added
- ./raftpb.EntryType.Number: added
- ./raftpb.EntryType.Type: added
- ./raftpb.EntryType_EntryConfChange: added
- ./raftpb.EntryType_EntryConfChangeV2: added
- ./raftpb.EntryType_EntryNormal: added
- ./raftpb.File_raft_proto: added
- ./raftpb.MessageType.Descriptor: added
- ./raftpb.MessageType.Number: added
- ./raftpb.MessageType.Type: added
- ./raftpb.MessageType_MsgApp: added
- ./raftpb.MessageType_MsgAppResp: added
- ./raftpb.MessageType_MsgBeat: added
- ./raftpb.MessageType_MsgCheckQuorum: added
- ./raftpb.MessageType_MsgForgetLeader: added
- ./raftpb.MessageType_MsgHeartbeat: added
- ./raftpb.MessageType_MsgHeartbeatResp: added
- ./raftpb.MessageType_MsgHup: added
- ./raftpb.MessageType_MsgPreVote: added
- ./raftpb.MessageType_MsgPreVoteResp: added
- ./raftpb.MessageType_MsgProp: added
- ./raftpb.MessageType_MsgReadIndex: added
- ./raftpb.MessageType_MsgReadIndexResp: added
- ./raftpb.MessageType_MsgSnap: added
- ./raftpb.MessageType_MsgSnapStatus: added
- ./raftpb.MessageType_MsgStorageAppend: added
- ./raftpb.MessageType_MsgStorageAppendResp: added
- ./raftpb.MessageType_MsgStorageApply: added
- ./raftpb.MessageType_MsgStorageApplyResp: added
- ./raftpb.MessageType_MsgTimeoutNow: added
- ./raftpb.MessageType_MsgTransferLeader: added
- ./raftpb.MessageType_MsgUnreachable: added
- ./raftpb.MessageType_MsgVote: added
- ./raftpb.MessageType_MsgVoteResp: added

```

Commands for reference:
```
$ go install golang.org/x/exp/cmd/apidiff@latest

$ cd {raft_repo_root_dir}

$ git checkout release-3.6
$ apidiff -m -w ~/api.raft_3.6 go.etcd.io/raft/v3

$ git checkout main
$ apidiff -m -w ~/api.raft_3.7 go.etcd.io/raft/v3

$ apidiff -m ~/api.raft_3.6 ~/api.raft_3.7 > raft_3.6_3.7_api.diff

```

cc @fuweid can you generate the diff for each module in etcd side? I think we most care about modules: `client/v3`, `client/pkg`, `api` and `pkg`.