ENG-8979;

Because we can just return empty ChangeThreadSettingsPayload we were able to update this here, not in each component. This simplified things a lot, implicitly handled loading status, and saved a lot of other work.

To fully support avatars I created ENG-9102.

Test:

1. Changing thread name
2. Changing thread description
3. Changing thread colors
4. Changing thread avatars (only emojis)