Revert "GrantedAuthority is working now. Todo: Cleanup"
Reason: My implementation was actually way to complicated.

This reverts commit f0f3ed4d0adebb88b72035332816c46a8cd72aee.
Revert "Implementing UserRoles as @ManyToMany. WIP"
Same as befor. Going back to simpler times.

This reverts commit 713f07c4ee9cc4a381ee45f611eab31e81f6aa40.
Implementation done