I don't think you'll find those cameras are fused like that. They probably have an inline fuse somewhere. But nothing as easy as resetting a circuit breaker.
Likely, the camera junction box behind your infotainment system has come disconnected. I don't know what info system you have. So, I can't tell you how to access the core unit.
Here's the wiring diagram for your Vista LX behind the "radio". All three cameras feed into video combiner/switcher and this plugs into the back of the radio.
Here's a screen shot of the specific wiring. But no instructions how to get to it. If you live in an area that has Auto Stereo Installers I'd hazard a guess that they could reconnect this quickly or tell you what's wrong. Or an RV dealer could do it in a couple of months, maybe.