Fixed bug in test which was passing but not testing the services_dao

correctly

The dao_fetch_monthly_historical_usage_by_template_for_service code
wasn't being tested properly due to an bug on the test which created a
notification with the same template and hence was not testing that
a specific service would have a different template id.

- Fixed the bug in the test
- Update services_dao so that the service id check is made

app/dao/services_dao.py

@@ -576,6 +576,7 @@ def dao_fetch_monthly_historical_usage_by_template_for_service(service_id, year)
         Template, Notification.template_id == Template.id,
     ).filter(
         Notification.created_at >= start_date,
+        Notification.service_id == service_id
     ).group_by(
         Notification.template_id,
         Template.name,