kvserver: account for cpu time spent processing raft transport stream per replica

**Is your feature request related to a problem? Please describe.**
Decompressing byte data and unmarshalling protos uses a noticeable amount of CPU. We record CPU usage used in replication per replica already [^1][^2][^3]. However, we don't attribute the raft transport CPU usage.

This issue is to attribute raft transport CPU use to a replica.

**Describe the solution you'd like**

Attribute the CPU usage of this function call, to the replicas the batch concerns:

https://github.com/cockroachdb/cockroach/blob/1d3c11efe8a5368cff3a3eec4668bf866c10952d/pkg/kv/kvserver/raft_transport.go#L504-L504

**Additional context**

Red outlined area shows the CPU to be attributed


[^1]: https://github.com/cockroachdb/cockroach/blob/1d3c11efe8a5368cff3a3eec4668bf866c10952d/pkg/kv/kvserver/store_raft.go#L380-L380
[^2]: https://github.com/cockroachdb/cockroach/blob/1d3c11efe8a5368cff3a3eec4668bf866c10952d/pkg/kv/kvserver/store_raft.go#L686-L686
[^3]: https://github.com/cockroachdb/cockroach/blob/1d3c11efe8a5368cff3a3eec4668bf866c10952d/pkg/kv/kvserver/store_raft.go#L714-L714