Update queries for data model change (removal of organisation_to_service)

New query to get letter breakdown.

tests/app/db.py

@@ -108,7 +108,8 @@ def create_service(
         check_if_service_exists=False,
         go_live_user=None,
         go_live_at=None,
-        crown=True
+        crown=True,
+        organisation=None
 ):
     if check_if_service_exists:
         service = Service.query.filter_by(name=service_name).first()