Ziafazal/add orgs to users api

@mattdrayer  @dino-cikatic add organizations to users api to support MCKIN-1512
I think really display_name is the thing of interest here... perhaps we don't need a separate display_name and name data - this is really a hold over from the group of type "organisation"... perhaps we remove display_name from the model and just use name. There will need to be an Apros update to avoid showing the name twice in the UI in that case, but that is straightforward.

(Incidentally, the same is not true for Programs, the 2 names are importantly distinct from each other... but this is not a concern for now)