Discussion: Figure out what to do with PV Sets

As a user of the system I can't use and don't understand PV Sets. This functionality should be either documented and finished or deleted.

Suggested resolution is a discussion of what to do.

### Acceptance Criteria

- [ ] Establish what stage of implementation they are in (before discussion)
- [ ] Establish whether we still need PV Sets, remove PV Sets from the code base if not.
- [ ] Tickets are made to
- remove and document reason
- fix, test and document the full functionality of PV Sets

### Notes

Originally discovered from #4951 , I wanted to add some data to the PV Sets table since that table uses checkboxes similar to the ones used in the Blocks table, where the bug of that ticket was found. The only IOCs to have this are Galils (stored in config.xml in ioc) and these do not show up in the configuration screen.

@FreddieAkeroyd said he might have a better way of implementing the original requirement