Expose the GeoEvent service to REST

PeterBirksmith

I would like the 'ArcGIS GeoEvent' service exposed as a REST call.  I realise that you can check the status of the service_names that exist in GEX however, this does not always mean that the main GeoEvent service is down.

This would be similar to the ArcGIS server REST status
https://localhost:6443/arcgis/admin/machines/localhost/status