Try to use the fullscreen controller with a windowed video window

For a simple video playback view, it should be investigated whether the video window could use the current fullscreen controller as playback controls.

Note that currently the fullscreen controller is an own window.

TODO

• Try to attach the fullscreen controller to the extra video window
• Check how resizing the fullscreen controller itself behaves, and whether it sticks to the frame of the video
• Check how resizing the video window behaves. Can fullscreen controller be moved simultaneously?