Code Refactor with how the game loads levels from files

The game loads levels from files differently, challenges are loaded differently, level editor and workshop levels. This needs to be ran on a global function

Start by tracing how the game loads levels from files for normal levels, challenges, level-editor content, and workshop levels. The refactor is done when these paths use one global function, but the issue does not name files or tests to run.

Written by the indexing model from the issue text.