feat: Remove z-level restriction for zone activities.

[vitalyo7]

Checklist

Required

• [x] I wrote the PR title in conventional commit format.
• [ ] I ran the code formatter.
• [x] I linked any relevant issues using github keyword syntax so it can be closed automatically.
• [x] I have committed my changes to new branch that isn't main so it won't cause conflict when updating main branch later.

Purpose of change

Note: : had to resubmit PR due to issues with my fork, should be good now. Update the code to ignore z-level differences when working with zones. This should make it easier to setup loot zones across the z-levels for easier loot managements, i.e. basements, roofs, apartments and LMOE. It was a bit annoying to carry the loot up/down stairs.

Describe the solution

Solution is to remove all checks for z-level, both in the GUI and code that interacts with zones.

Describe alternatives you've considered

None. I think zones are currently the best way to manage loot, and just need to tweak them to work properly.

Testing

Additional context

This is half-tested. I compiled the code, did some zone setup in my LMOE bunker and asked my main char to sort out the loot. Seem(s) like it worked. However more testing will likely be required. Volunteers appreciated.