FEATURE: ONVIF needs to be able to have directions flipped

[RoboKaren]

So some cheap ONVIF cameras are dyslexic in that LEFT is RIGHT and RIGHT is LEFT. We need a simple feature toggle so that we can say FLIP_HORIZONTAL_CONTROL or FLIP_VERTICAL_CONTROL.

Yeah, it's a bug in the camera but a simple one to handle on the Frigate backend.

[RoboKaren]

Another "feature" switch would be to turn off the zoom controls on devices that don't have zoom capability.