add add one-off notification status

completely mimicks the job status page, and as such, all the code and
templates have been taken from the job page. This page performs
exactly the same as the job page for now

* total, sending, delivered, failed blue boxes (though they'll just
  read 0/1 for now.
* download report button (same as with job download, except without job
  or row number in file)
* removed references to scheduled
* kept references to help (aka tour/tutorial) as that'll eventually
  change over from a job to a one-off too

app/notify_client/notification_api_client.py

@@ -55,7 +55,5 @@ class NotificationApiClient(NotifyAdminAPIClient):
                 params=params
             )
 
-    def get_notification(self, service_id, notification_id):
-        return self.get(
-            url='/service/{}/notifications/{}'.format(service_id, notification_id)
-        )
+    def get_notification(self, service_id, notification_id):m
+        return self.get(url='/service/{}/notifications/{}'.format(service_id, notification_id))