Social proof

[dirkmc]

When you view a user’s profile we’d like to provide some details about followers of the given account that you follow. This establishes social connections between the two users, and we hope that it will facilitate users discovering their broader clusters and ultimately following each other. Here’s an example:

This PR adds a socialProof to the viewer section of the profile, eg:

{
    ...
    socialProof: {
      count: 1,
      follows: [
        {
          did: 'did:plc:x3bne6hoa7xokmoccsqzgxvm',
          handle: 'bob.test',
          displayName: 'bobby',
          avatar: 'https://bsky.public.url/img/avatar/plain/did:plc:x3bne6hoa7xokmoccsqzgxvm/bafkreiaivizp4xldojmmpuzmiu75cmea7nq56dnntnuhzhsjcb63aou5ei@jpeg',
          viewer: [Object],
          labels: []
        }
      ]
    }
}

The PR implements

• a getFollowsFollowing({ actorDid, targetDid }) method at the data-plane layer, that returns a list of dids
• hydration:
  • the socialProof element of the ProfileViewerState with a count and follows for the first 5 dids returned from the data-plane layer
  • each did is hydrated into a profile on the HydrationState
• a view layer that maps each of the follows into a basic profile

[estrattonbailey]

Thanks @dirkmc! Gonna merge into the base and take it from here 👍