C++ Values LocalCoordinates is backwards

[aaron-skydio]

#395 (comment)

Values::LocalCoordinates(v) produces v - this, which is the negative of what's used everywhere else. On the geo types and cam types, and Values.local_coordinates in Python, it returns this - v

[aaron-skydio]

As far as which is correct, I think the convention everything else uses is more intuitive, plus it's much less of a breakage to change Values::LocalCoordinates than everything else.

Above all else though, they should all be consistent (all of the instance methods, at least)