We modify useRemoveUserAvatar to return a tuple of useRemoveUserAvatar, isLoading.
In subsequent diff will consume this along w/ isLoading from useSelectFromGalleryAndUpdateUserAvatar` to render a spinner over the image when operation is in progress.
For convenience, I'm going to have a multiple diffs where I update the EditUserAvatar flow, and then a single diff where I update the EditThreadAvatar flow to match. There's a lot of repetition, but I have ideas on how to consolidate things once we have a shippable experience.
Depends on D7527