Add in-line friend request in groups

[cstiens]

This would show up in unencrypted groups if a person that you're not friends with sends an image. We are not auto-downloading that image. Here's ticket #457 for reference. Below is the UI for this case. I've also attached the blurred image to use as a placeholder for an image that is not downloaded.

The idea was to use the download icon as a processing indicator also. I imagine something like this for the circular animation—https://cdn.dribbble.com/users/15774/screenshots/1759511/spinner.gif I realize this is showing 'processing' not 'progress', but it feels more productive because there's more movement. We would show the % where we currently do under the avatar.

[N-Pex]

@cstiens So the green one sends a friend request, what happens then? Also, I am unsure what the red button would do in this case?