[lib] update message reducer to use ops approach for local field

Summary:
Refactor the local field in the message reducer + relevant util functions in this file to use the ops approach

Depends on D12357

Test Plan:
Tested each action type w/ @will during the hackathon, and we were able to confirm that we were getting the expected behavior for each action

Some of the main user flows we tested:

1. fail sending a message
2. successfully retry sending a message
3. closing the app where a thread had a bunch of sent failed local messages
4. fail sending a reaction message
5. deleting a thread with a bunch of sent failed messages

Reviewers: will, tomek, kamil

Reviewed By: tomek

Subscribers: ashoat, tomek, will

Differential Revision: https://phab.comm.dev/D12358