add numerous geodetic / spherical transforms from @rpavlick

Thanks to @rpavlick for adding numerous functions in rcurve, rsphere, latitude, lox, utils and more.
These functions each had tests written.
Further, some Numpy functionality that was accidentally removed from v2.0 was restored for v2.1.

The goal of the PyMap3D package remains to support non-Numpy users, while also fully supporting those who have Numpy. The non-Numpy users are typically robots or platforms that stream positions in realtime, and don't need arrays, and want the faster performance of Python's built-in math module.