Convert codebase to typed luau

[1ForeverHD]

This is something I'd eventually like to do although likely won't tackle until Nanoblox is released. This is because the codebase started ~1 year before type checks existed and I'd prefer to release Nanoblox first than aim for complete perfection.

Useful resources:

• https://devforum.roblox.com/t/type-checking-for-beginners/1027242
• https://luau-lang.org/typecheck

Also consider modifying Enum to function in a similar way to this: https://twitter.com/sleitnick/status/1510968031421288449