Sort services and orgs in presentation layer

The model layer shouldn’t need to be concerned with sorting. For
services this means we can make a `SerialisedModelCollection` rather
than writing a manual loop.

app/models/user.py

@@ -293,9 +293,9 @@ class User(JSONModel, UserMixin):
     @property
     def services(self):
         from app.models.service import Service
-        return sorted(
+        return [
             Service(service) for service in self.orgs_and_services['services']
-        )
+        ]
 
     @property
     def services_with_organisation(self):