Image Controls

[EricBAndrews]

Checklist

• I have read CONTRIBUTING.md
• I have described what this PR contains
• If this PR alters the UI, I have attached pictures/videos
• This PR addresses one or more open issues that were assigned to me:
  - closes #issue
  - progress towards #issue

Pull Request Information

Replaces the image viewer context menu with a control layer.

Intended behavior:

• Control layer is shown when viewer first opens
• For non-animated media: control layer appears/disappears on tap
• For animated media:
  • When playing: control layer appears/disappears on tap outside of media's frame (i.e., in the black margins)
  • When not playing: control layer appears/disappears on tap anywhere but the play button

This PR also removes the ProgressView from AnimationControlLayer. Media loading is almost always fast enough that the ProgressView is just visual clutter, and in rare cases a gif advertises itself as "animated" but isn't and leaves the ProgressView spinning on top of it (I don't have a repro example handy, but I have seen it a couple times).