Change the get notifications for a month to call a new summary table

[jzbahrai]

Summary | Résumé

Change the get notifications for a month to call a new summary table
This is because the summary table only stores data for a month, vs day (which is what ft_notification_status does).
This table is a lot faster to answer the question how many notifications have been send by notify.

DONOT MERGE, will test this after code freeze and then merge

We can assume atleast the data in the table is correct, as if I go and query production, I see

select month, notification_type, sum(notification_count) from monthly_notification_stats_summary where month >='2025-11-01' and month <='2025-11-30' and service_id not in ('30b2fb9c-f8ad-49ad-818a-ed123fc00758', 'd6aa2c68-a2d9-4437-ab19-3ae8eb202553') group by 1, 2 ;
         month          | notification_type |   sum
------------------------+-------------------+---------
 2025-11-01 00:00:00+00 | sms               |  295562
 2025-11-01 00:00:00+00 | email             | 9261689

which is the same as

which currently calling ft_notification_status

(after this PR is merged, we will be using the new table)