input: handle click to pause during video playback

Refs #8369

The default mouse event is forwarded to the player to handle play/pause functionality. However, it can be overridden in cases where mouse event has it's own navigation functionality (e.g., MKV, DVDNav, and Blu-ray).

Note: This does not currently work with files using mkv demuxer because the mkv demuxer always registers mouse events. Can the mkv demuxer be handled to send mouse events only when needed?