Update files, directories and code to match naming convention

From https://github.com/hackerspace-ntnu/Prosjekt-Spill-H22/issues/19#issuecomment-1450972419, the conventions are as follows:

- Files and folders:
- `PascalCase`
- Types (classes/structs):
- `PascalCase`
- Interfaces:
- `IPascalCase`
- Methods:
- `PascalCase`
- Local functions (i.e. nested):
- `camelCase`
- Properties:
- `PascalCase`
- Local variables:
- `camelCase`
- Local constants:
- `camelCase`
- Parameters:
- `camelCase`
- Fields (not private):
- `PascalCase`
- Fields (private):
- `camelCase`
- Static fields (private):
- `camelCase`
- Constant fields:
- `SCREAMING_SNAKE_CASE`
- Static readonly fields (not private):
- `PascalCase`
- Static readonly fields (private):
- `camelCase`
- Enum members:
- `SCREAMING_SNAKE_CASE`