Bring in the room mapping from notman-ss-dashboard

[ajmas]

We should bring in the logic from the room mapping, used in the notman-ss-dashboard project and make it part of the events service. This would allow for a common place to map the names, rather than duplicating this in various locations.

This would impact the JSON sent back, such that:

{
     room-ref: 'floor3',
     display-name: {
         fr: '3ieme étage',
         en: '3rd Floor'
     }
}

Not sure if the navigation hints should be local to the screen or sent back from the API server?