Desktop: Support high framerate videos and synchronize video to audio

[dasisdormax]

Similar to #85, this synchronizes the video to the audio and makes sure that the video timing still works when the window is resized. In addition, this fixes playback of high-fps video on slower monitors, by requesting multiple frames from the decoder if needed.

I tested with regular and silent video, but only on Mac so far.

Also: @Frosty-J, I am sorry for the collision with your PR.