Sarpy

Added
- Added tests for sicd_elements for SICD.py and RadarCollection.py.
Changed
- test_sicd_elements.py was split up into smaller more easily manageable python files.
Fixed
- Fixed bug in SARPY correctly specifying SCP when instantiating GeoDataType in SICD.py
- Fixed spelling error for override parameter in SICD.py, base.py, SIDD.py, Fiduciallnfo.py,
ObjectInfo.py, blocks.py, projection_helper.py.

Changed
- Changed geotiff2deg.py, user must now explicitly specify DEM reference
surface, or accept default value of EGM2008.
- Changed converter.py, and convert_to_sicd.py updated to reflect changes
to geotiff2deg.py.

Fixed
- Fixed bug with readthedocs correctly building documentation per
[readthedocs.org issue 10290](https://github.com/readthedocs/readthedocs.org/issues/10290)
and [sphinx-doc issue 10378](https://github.com/sphinx-doc/sphinx/issues/10378).

Added
- Added X1Y1 vs X2Y2 checks to cphd_consistency and test_cphd_consistency.

Added
- Added support for DEMs in GeoTIFF format.
- Added projection to a DEM for SCP and image corner coordinates in
sarpy/utils/convert_to_sicd.py and sarpy/io/complex/converter.py modules
when a GeoTIFF DEM file is used as a CLI argument in convert_to_sicd program.

Fixed
- Fixed bug in SARPY correctly reading numerous nitf files in linux OS.
Changed
- Minor cleaning in nitf.py.