Revision/revise coord trafo
- Fixed issue of remaining coverage artifacts after running 'make clean-test.
- Revised coord_trafo.py. This fixes an issue that caused pixelToLatLon() to return Lon/Lat instead of Lat/Lon.
- Fixed mapXY2imXY() and imXY2mapXY().
- Added Test_mapXY2imXY(), Test_imXY2mapXY(), Test_pixelToLatLon(), Test_latLonToPixel().
- Removed GDAL dataset input parameters from some functions.
- Revised code style and some docstrings. Added some typehints.
- Bugfix for always raising a RuntimeWarning in fill_holes_within_poly().