[native] implement leaving DM thread
Summary:
ENG-8977
Updating component logic.
Test Plan:
- Created thread with users A and B.
- On A leave thread.
- B see that A left, thread disappeared for A.
Reviewers: tomek, inka
Reviewed By: tomek
Subscribers: ashoat
Differential Revision: https://phab.comm.dev/D13184