[lib] Create thread store ops from updates in a spec

Summary:
Move the logic from a reducer to specs.

Depends on D9244

https://linear.app/comm/issue/ENG-4590/describe-which-ops-are-generated-from-a-redux-action-in-a-spec

Test Plan: Open two clients and check if making operations (e.g. updating or joining a thread) generates the right ops on the other.

Reviewers: kamil, bartek, inka

Reviewed By: kamil

Subscribers: ashoat, michal

Differential Revision: https://phab.comm.dev/D9245