Add operations to gather data from Booker get_rooms result

We are only interested in buildings, floors (actually just a string), sites and departments associated with the filtered (with TermTime equipment note) list of rooms from Booker.

Add operations that use the get_rooms results (call it if no booker.rooms) to build lists of these.

• get_buildings
• get_floors
• get_sites
• get_depts

Hopefully you won't need to fill out these with actual API calls for more data.