[Sprint/QuietQuail](fix): Avatar changing forms now change avatar without refresh of components

Closes #2197 (closed) #2087 (closed) #1835 (closed) and half of #2082 (closed)

Testing

I think it'd be best to spin this up on a subdomain connected to live data, like revolver; so that it can be tested on the live site.

This makes changes to avatars site-wide, user avatars, and group avatars.

To test:

1. Create a new account.
2. Upload an avatar - check it updates everywhere.
3. Create a comment on a post with current avatar.
4. Change avatar.
5. Create a second comment on a post, avatar on all comments should match current avatar of channel.