Patched AddUser class for manager role

This is kind of a ghetto patch instead of a refactor which would take a
lot more time than we don't have. It still works fine as far as I know.

Also resized supermarket GUI to not be too small.
Added supplier ability to view comments about themselves
Merge branch 'master' of https://github.com/truly-auto/SENG403
resolving conflicts
added a confirmation window for successful submission of orders