Create query to sum notificaitons for the message limit check, this is a bit more efficient.

Refactored send_notifications method so that it is more readible.
Refectored the test_send_notificaitons so that it uses parametrized test to avoid duplication.

app/dao/services_dao.py

@@ -150,6 +150,20 @@ def dao_fetch_todays_stats_for_service(service_id):
     ).all()
 
 
+def fetch_todays_total_message_count(service_id):
+    result = db.session.query(
+        func.count(Notification.id).label('count')
+    ).filter(
+        Notification.service_id == service_id,
+        Notification.key_type != KEY_TYPE_TEST,
+        func.date(Notification.created_at) == date.today()
+    ).group_by(
+        Notification.notification_type,
+        Notification.status,
+    ).first()
+    return 0 if result is None else result.count
+
+
 def _stats_for_service_query(service_id):
     return db.session.query(
         Notification.notification_type,