[lib] Update reduceThreadActivity to handle processUpdatesActionType and others

Summary:
To address @tomek's point here: https://phab.comm.dev/D9402#276831

Went ahead and added all the actionTypes for that could include ClientUpdateInfo. @tomek wanted to get your thoughts on this approach, or if I should just add processUpdatesActionType.

Added an additional filter check to see if there were any DELETE_THREAD updates before creating a new state object as an optimization since presumably this action handler branch will be hit more times now.

Test Plan: Careful reading + flow, not sure if further testing is worthwile.

Reviewers: ashoat, tomek, rohan, ginsu

Reviewed By: tomek

Subscribers: wyilio, tomek

Differential Revision: https://phab.comm.dev/D9453