4K upscaled videos lag

[KitsuneNoBaka]

@balko

Yes, mpv/smplayer should be made the default media player in Qubes OS’s default templates, because Gnome/xfce players are slow and bad. I was surprised how out-of-box video-players are bad in Qubes OS, especially considering it uses only CPU to play video.

Maybe because templates are as much as possible upstream. As small changes as possible.