ChestMenu per player in UU category

Short Description

Made a chest menu per player in UU category

Moved stuff around so that there is a chest menu per player in UU category

uu category is weird with multiple people in it

[x] I have fully tested the proposed changes and promise that they will not break everything into chaos.
[x] I have also tested the proposed changes in combination with base Slimefun and made sure nothing breaks/unexpected happens.
[ ] I followed the existing code standards and didn't mess up the formatting.
[ ] I did my best to add documentation to any public classes or methods I added which may not be obvious to maintainers.
[ ] I have added Nonnull and Nullable annotations to my methods to indicate their behaviour for null values