port colortbl.h generation script to Python

port colortbl.h generation script to Python

Note that this does not introduce an extra build dependency in any of the three
build systems:

  1. Autotools: these steps are done during construction of the portable source
     tarball, during which Python 3 is already required (see autogen.sh).

  2. CMake: Python 3 is already required by and used in the top level
     CMakeLists.txt.

  3. MS Build: Python 3 is already used in version generation in
     lib/version/version.vcxproj.

This change is motivated by the goal of removing a dependency on Awk. This
commit removes the last remaining Awk usage in all three build systems, as well
as removing dependencies on `type` and `sort` in the MS Build build system.

This commit removes the generation of the intermediate artifacts color_lib,
color_lib-sort, and color_lib-temp. Instead, we generate only the final
artifact, colortbl.h. This consolidation of logic into Python is part of what
allows the removal of dependencies described above.

Gitlab: #2118