[REF] mv rb related code to its module
[REF] mv rb xml handler into rb module
[REF] made booking deletion an admin handler
[MIN] import fix for rb admin rh
[MIN] typo fix
[REF] admin index controller/view for new structure

- simplification (flask.request + drop extra init)
- imports
- pep8
[REF] admin location controller/view for new structure
[REF] percentage as a util method
[REF] user room rh/view