[lib] Update UPDATE_RELATIONSHIP.rawMessageInfoFromClientDB to handle farcaster_mutual

Summary:
Same as D11652, but for clientDB. Separated diffs because they have different Test Plans that will be filled out.

Depends on D11652

Test Plan: Will create some UPDATE_RELATIONSHIP messages w/ farcaster_mutual operation and ensure that they appear in clientDB as expected.

Reviewers: varun, ginsu, tomek, will

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D11653