Allow for club room grants

[TheEgghead27]

For certain clubs (e.g. Math Team for "Math Team Rooms" as they do not like sharing, or other strong clubs that get specific rooms) it should be possible for them to bypass restrictions on a specific room listing that is not public (e.g. room 123 is generally blocked on Mondays, but the Garfield club is allowed to book meetings in that room [not necessarily only that room - enforcement is up to clubs/pubs] regardless because the block is for them)