[Enhancement] Support external scripting

[NewGBAXL]

Adding new games will always be high-demand, so I'm proposing supporting external scripting languages, such as Python or Lua, so that developers can easily implement new games without touching the central C source.

The model formats themselves would always be handled by the central program, but the "glue" for batch management on a per-game basis would be done externally.

External scripting would open up the ability to the average user to support new games.