Process Incomplete Jobs Updates

Comments are PR review. Updated code style in a few places to make it
more consistent with other code, added tests for letters and emails
so they are testedt, refactored some database queries to dao file

- Fixed code style
- Refactored database queries to dao code
- Added tests for emails and sms.

app/dao/notifications_dao.py

@@ -640,3 +640,14 @@ def dao_get_notification_email_reply_for_notification(notification_id):
 
     if email_reply_to:
         return email_reply_to.email_address
+
+
+@statsd(namespace="dao")
+def dao_get_last_notification_added_for_job_id(job_id):
+    last_notification_added = Notification.query.filter(
+        Notification.job_id == job_id
+    ).order_by(
+        Notification.job_row_number.desc()
+    ).first()
+
+    return last_notification_added