Bug 36572: Fix and clean-up set library

Bug 36572: Fix and clean-up set library

To test:
1. Have 3 staff accounts to test:
  -STAFF A: superlibrarian
  -STAFF B: loggedinlibrary permission
  -STAFF C: no loggedinlibrary or superlibrarian permission
2. Enable 'UseCirculationDesks' and create some desks. (Admin >
   Circulation desks)
3. Enable 'UseCashRegisters' and create some registers ( Admin > Cash
   registers)
4. Use STAFF A ( superlibrarian ) and make sure you can change branch,
   desk and register.
5. Use STAFF B ( loggedinlibrary permission ) and make sure you can
   change branch, desk and register.
6. Use STAFF C ( no loggedinlibrary or superlibrarian permission ) and
   make sure you can change branch, desk and register.
7. Each time you change you should be redirected to the page you were
   previously on.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>