OBS Virtual Camera support on Linux

[Avasam]

Is your feature request related to a problem? Please describe.

My c920 webcam simply won't work (may or may not be a vmware issue).
I can't get the virtual cam working in OBS.
So I can't test or implement this feature myself 😕 (for all I know it's already working as-is).

Describe the solution you'd like

It should be possible to use OBS Virtual camera with AutoSplit on Linux.
Webcam/Capture device support optional.

Additional context

Extracted from #224

v4l2loopback Video Devices don't work atm Avasam#55