Loosen key restriction on get notification

Currently getting a single notification by ID is restricted to
notifications created with the same key type.

This makes things awkward for the functional tests now we’ve removed the
ability to create live keys in trial mode. So this commit removes the
restriction, so that any key can get any notification, no matter how it
was created.

And you’re never going to guess a UUID, so the chances of this giving
you privileged access to someone’s personal information is none.

This does not change the get all notifications endpoint, which
absolutely should be restricted by key type.

app/notifications/rest.py

@@ -159,7 +159,7 @@ def process_firetext_response():
 def get_notification_by_id(notification_id):
     notification = notifications_dao.get_notification_with_personalisation(str(api_user.service_id),
                                                                            notification_id,
-                                                                           key_type=api_user.key_type)
+                                                                           key_type=None)
     return jsonify(data={"notification": notification_with_personalisation_schema.dump(notification).data}), 200