Fixes #2482

And also add proj_context_errno_string()

Revise gie 'expect failure errno XXXX' strings

The big size of coordinateoperation.cpp could require significant amount
of RAM to build it with -O2 level, and cause compiler crashes in some
environments.

Add option to allow export of Geographic/Projected 3D CRS in WKT1_GDAL

Remove proj_api.h

as CompoundCRS with a VerticalCRS being an ellipsoidal height, which is
not conformant. But needed for LAS 1.4 that only supports WKT1