Compatibility changes

- Removed `mixed` function return type from some functions for backward compatibility with php 7.4
- Refactored string concatination for readability.
- Added TODO for later
- Corrected PHPdocs
- Removed unneeded TODO
- Refactored function names with mixed snake and pascal case names
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f