Draft: Add basic mono tracking for psmv

Created in response to #390 .

I have tested these changes somewhat on my system, it displays a single view in the debug gui, but it will definitely need some work before it is useful. In particular, I'm not sure what transformation would work for going from camera space to world space; another downside is that it repurposes StereoRectificationMaps and StereoCameraCalibrationWrapper .