MPG, MPEG support

[grdw]

Currently in Spaceship we have a video thumbnailer. In Spaceship we check the file extension instead of actually using the format parser (mainly because changing the file extension on mobile is quite uncommon). However, we still have plans to use the format parser for this, if only it supported MPG and MPEG (and M4V, but that's probably a bit different so I'll create a different issue for that one).

I'm wondering if and how this is possible.

Related: https://github.com/WeTransfer/spaceship/issues/1975