Remove GDAL library, replace with Python geotiff library

[mkrupczak3]

The official GDAL library is an extensive suite of open-source GEOINT tools for use by professionals.

The OpenAthena project has made use of this library as a pre-requisite so far, but some issues arise due to the following:

• Installing GDAL with the python pygdal library fails on multiple OS's (and has for some time) with no known fix
• GDAL can only be installed with the OS's package manager. This is a problem for OS's like Mac and Windows which do not come with a package manager by default

Therefore, to improve the process of installing and using this software the GDAL Library will be excised and replaced with @KipCrossing's python geotiff library

This library is narrower in scope and is viable for extracting a usable Digital Elevation Model from a given GeoTIFF

[mkrupczak3]

Currently there is a serious regression in the OpenAthena code after having migrated from the GDAL to the geotiff library: rotated or skewed GeoTIFF files are no longer recognized and rejected. Attempting to run a rotated or skewed GeoTIFF with OpenAthena will result in undesirable, undefined program behavior

Given the status of OpenAthena as an experimental project still in pre-alpha, I could still make this change. I am loathe to do so however until this regression is solved

[mkrupczak3]

Currently there is a serious regression in the OpenAthena code after having migrated from the GDAL to the geotiff library: rotated or skewed GeoTIFF files are no longer recognized and rejected. Attempting to run a rotated or skewed GeoTIFF with OpenAthena will result in undesirable, undefined program behavior

Given the status of OpenAthena as an experimental project still in pre-alpha, I could still make this change. I am loathe to do so however until this regression is solved

Screw it, I'll do this later

Merging #19 to main