Fixed an unhelpful error message in case no coregistration point can be placed within an image area usable for coregistration due to the provided bad data mask. Fixed some wrong type hints. Added COREG_LOCAL.calculate_spatial_shifts() allowing to explicitly compute the shifts instead of implicitly running the getter properties. This improves API clarity and facilitates debugging. Added sphinx-autodoc-typehints to doc requirements.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>