Summary:
Eventually, notification stuff should be moved out of InboxAPI into a separate package, and we should have some documented way of watching for "new" things. (Right now it'd be a bit hard to do on the database store...)
Additional fixes:
- AddRemoveTagsTask now optimistically updates the version. Before it would get the new version from the API response. This was bad because it could still cause local changes to be overwritten if you were changing tags really fast.
- AddRemoveTagsTask now takes a threadId, not a thread for consistency with all the rest of our Tasks
Test Plan: Run tests
Reviewers: evan
Reviewed By: evan
Differential Revision: https://review.inboxapp.com/D1214
