Remove/revamp unused .gd scripts in menu_scenes/level_select folder

[coderabbitai]

Background

The .gd scripts in the menu_scenes/level_select folder are currently unused and planned for removal during the development process.

Task

• Review all .gd scripts in menu_scenes/level_select/ folder
• Remove unused scripts like level_select_menu.gd
• Revamp any scripts that should be kept but need updates

Context

• Current script has commented-out level population logic
• Script will be removed at a later point in development
• Part of general cleanup of legacy/unused code

References

• PR: Add game controller singleton #7
• Comment: Add game controller singleton #7 (comment)

[nathan-coleman]

The plan here is to switch these over to c# - well, pretty much scrap them. However I want to keep them around as there are some ideas in here that I want to ponder for save game loading.