More logical column order

We had status - name - updated at - concerning - about, now we swap updated at and concerning
Refactor the websocket notifications observer as concern

Having it as a concern instead of observer allows us to do more and this also means we only need to refactor the cache sweeper now to get rid of the activerecord-observers gem.

The main motivation for this was to also include the new tickets into the websocket notifications framework.
include WebsocketMessages

Now we can rely on websocket events instead of polling for ticket status.
Translate to coffeescript
Use websockets instead of polling for updating tickets