WIP: Move Nuitka build to GitHub Actions

[qstokkink]

Fixes #97

This is a WIP/Test PR. Stay tuned.

TODO:

• Enable Mac builds.
• Enable Ubuntu builds.
• Move built executable out of build directory.
• Locate and ship libsodium DLL.
• Locate and ship libcrypto-1_1 DLL.
• Locate and ship libcrypto-1_1-x64 DLL.
• Locate and ship libssl-1_1 DLL.
• Locate and ship libssl-1_1-x64 DLL.
• Build ui using npm and ship the resulting dist directory.
• Fix pony assertion errors:

  File "pony\orm\core.py", line 4027, in select
  File "pony\orm\core.py", line 4388, in _query_from_args_
AssertionError

  File "pony\orm\core.py", line 4017, in get_for_update
  File "pony\orm\core.py", line 4114, in _find_one_
  File "pony\orm\core.py", line 4171, in _find_in_db_
  File "pony\orm\sqlbuilding.py", line 191, in adapter
  File "pony\orm\sqlbuilding.py", line 191, in <genexpr>
  File "pony\orm\sqlbuilding.py", line 34, in eval
AssertionError

[qstokkink]

I assumed fixing the PonyORM errors would be a small hurdle. Upon further inspection, this is a deal breaker.

• For PonyORM the co_code of functions is the primary mechanism to determine the SQL mappings.
• For Nuitka the co_code of functions is the one thing that is not implemented.

Faced with this mutual exclusion, considering PonyORM is already in our code base and Nuitka is not, we should drop Nuitka.