* Support a swipe down to dismiss video
Images can already be dismissed with a swipe, this adds the same
functionality to videos.
- Add a VideoActionsListener interface for the hosting activity to dismiss
the fragment
- Add a gesture listener for swipes
- Dismiss the fragment if a swipe has a greated Y component than X
Fixes https://github.com/tuskyapp/Tusky/issues/2833
* Scale the video view when dragging
Provides identical visual feedback to the same operation on images.
64a06bfbe2