[lib] generate message store ops for threads after sending message

Summary:
This code generates operations needed for updating threads part of message store after message was sent with success.

Depends on D7417

Test Plan: Try to send message (with success) using different flows on both web and native

Reviewers: tomek, marcin

Reviewed By: tomek

Subscribers: ashoat, atul

Differential Revision: https://phab.comm.dev/D7418