Added displaying 'Edit' label next to edited messages.

Tested displaying on both sides (left and right) with:

1. message not edited and without thread/reactions,
2. message edited without thread/reactions,
3. message not edited with thread/reactions,
4. message edited with thread,
5. message edited with reactions,
6. message edited with thread and reactions,
7. many edited messages in a row,

Screenshots:
[1, 2, 3, 5, 6]