[lib] Re-introduce RelationshipRequest and replace TraditionalRelationshipRequest where simple
Summary:
Re-introduce RelationshipRequest as union of TraditionalRelationshipRequest|FarcasterRelationship and replace TraditionalRelationshipRequest where simple.
Next steps are to
- Narrow TraditionalRelationshipRequest so it excludes farcaster action
- Update FarcasterRelationshipRequest callsite
- Make necessary changes on keyserver to accomodate
Depends on D11603
Test Plan: flow
Reviewers: varun, ginsu, will, tomek
Reviewed By: ginsu
Subscribers: ashoat
Differential Revision: https://phab.comm.dev/D11605