Substrate v3 Migration: Types/API changes tracking

Tracking the changes to runtime, types, storage, and dispatchable calls (if any) that were absolutely required as a result of updating runtime from version 2.0.1 to latest v3 (0.9.23) of substrate.

Membership Pallet

• Changed MembershipById storage map value from: Membership to Option<Membership>

/// Mapping of member's id to their membership profile.
pub MembershipById get(fn membership) : map hasher(blake2_128_concat)
    T::MemberId => Option<Membership<T>>;

ref: https://github.com/Joystream/joystream/issues/3876#issuecomment-1151927859

Council Pallet

• Changed Candidates storage map value from Candidate to Option<Candidate>

/// Map of all candidates that ever candidated and haven't unstake yet.
pub Candidates get(fn candidates) config(): map hasher(blake2_128_concat)
    T::MemberId => Option<Candidate<T::AccountId, Balance<T>, T::Hash, VotePowerOf::<T>>>;

Working Groups Pallet

• Changed ApplicationById storage map value from Application to Option<Application>
• Changed WorkerById storage map value from Worker to Option<Worker>

/// Maps identifier to worker application on opening.
pub ApplicationById get(fn application_by_id) : map hasher(blake2_128_concat)
    ApplicationId => Option<Application<T>>;

/// Maps identifier to corresponding worker.
pub WorkerById get(fn worker_by_id) : map hasher(blake2_128_concat)
    WorkerId<T> => Option<Worker<T>>;

Storage Pallet

• Changed StorageBucketById storage map value from StorageBucket to Option<StorageBucket>

/// Storage buckets.
pub StorageBucketById get (fn storage_bucket_by_id): map hasher(blake2_128_concat)
     T::StorageBucketId => Option<StorageBucket<T>>;

Start with the Membership, Council, Working Groups, and Storage pallet storage declarations listed in the issue, then compare their runtime, types, storage, and dispatchable-call usage between Substrate 2.0.1 and v3 (0.9.23). Done means all required migration changes are identified and the affected declarations or usages are updated consistently.