Corners API

A lot of people ask for passthrough video access, which clearly has privacy concerns.  A simpler and safer way to get us 80% of the way there would be to using something like Harris Corner Detection https://opencv24-python-tutorials.readthedocs.io/en/latest/py_tutorials/py_feature2d/py_features_harris/py_features_harris.html

Providing developers with an API that providers corners in view, would allow an easy room calibration process for better AR / Mixed reality experiences without surrendering the raw video feed.