[native] Remove ChatThreadList class component
This diff finally removes the ChatThreadList class component altogether.
That said, this functional component is still cluttered and hasn't been optimized. I will work to declutter ChatThreadList and improve performance in subsequent diffs.
Depends on D9190
Test Plan: Everything continues to work as expected/before!
Reviewers: ginsu, tomek, rohan
Reviewed By: ginsu
Differential Revision: https://phab.comm.dev/D9191