Implement fake ps move external device emulation

[Megamouse]

• Adds external device emulation (sharpshooter, racing wheel) to fake PS Move and mouse PS move.

This already worked if a device was attached to a real PS move, but there was no way to activate it with the fake move options.
I never tested the racing wheel, so that might not work properly at all yet.

TODO:

• Test sharpshooter
• Test racing wheel
• Propagate racing wheel buttons as digital_buttons (both emulated and real) ?

Fixes #17042

[obi0ne]

Question, assuming the external mock/fake works, in order to make actual sharpshooter work we need to process the video from the pseye camera (or is that code already hooked in) ?
I have back at home sharpshooter & psmove + joystick + camera (pseye), I might be able to assit in the coding, but unfamilier with the current code base.
Do we have support & some infrastructure that process the video frame, so I may invoke some openCV to detect the blobs?

[Megamouse]

The sharpshooter is already working.
I'm just emulating it but I got distracted.
It's just grunt work to be honest.
I'll probably continue soon if I have time