Support non-show non-movie generic video

[faissaloo]

Is your feature request related to a problem? Please describe. It would be useful to use Dim to catalog and serve small-scale video content such as videos downloaded from PeerTube.

Describe the solution you'd like Instead of using TMDB, metadata could be extracted via ffprobe, and if that metadata isn't present a 'best effort' to generate something sensible should be used (e.g: titlizing the filename and removing the extension).

This could be a third option in the UI in the library creation screen.