Sales MVC

- Added todo to Stock_location.php
- make library function return nullable
- Added missing model instantiation
- Commented out Sale model instantiation in library because it's causing infinite loop
- Changed function name prepending get and post required by CI4 autorouting
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