Refactor send_user_email_verification to persist the notification then put on the "notify" queue for delivery.

The reason for doing this is to ensure the tasks performed for the Notify users are not queued behind a large job, a way to
ensure priority for messages.

app/user/rest.py

@@ -18,7 +18,7 @@ from app.dao.users_dao import (
 from app.dao.permissions_dao import permission_dao
 from app.dao.services_dao import dao_fetch_service_by_id
 from app.dao.templates_dao import dao_get_template_by_id
-from app.models import SMS_TYPE, KEY_TYPE_NORMAL
+from app.models import SMS_TYPE, KEY_TYPE_NORMAL, EMAIL_TYPE
 from app.notifications.process_notifications import (
     persist_notification,
     send_notification_to_queue
@@ -203,21 +203,22 @@ def send_user_email_verification(user_id):
     create_user_code(user_to_send_to, secret_code, 'email')
 
     template = dao_get_template_by_id(current_app.config['EMAIL_VERIFY_CODE_TEMPLATE_ID'])
-    message = {
-        'template': str(template.id),
-        'template_version': template.version,
-        'to': user_to_send_to.email_address,
-        'personalisation': {
+
+    saved_notification = persist_notification(
+        template_id=template.id,
+        template_version=template.version,
+        recipient=user_to_send_to.email_address,
+        service_id=current_app.config['NOTIFY_SERVICE_ID'],
+        personalisation={
             'name': user_to_send_to.name,
             'url': _create_verification_url(user_to_send_to, secret_code)
-        }
-    }
-    send_email.apply_async((
-        current_app.config['NOTIFY_SERVICE_ID'],
-        str(uuid.uuid4()),
-        encryption.encrypt(message),
-        datetime.utcnow().strftime(DATETIME_FORMAT)
-    ), queue='notify')
+        },
+        notification_type=EMAIL_TYPE,
+        api_key_id=None,
+        key_type=KEY_TYPE_NORMAL
+    )
+
+    send_notification_to_queue(saved_notification, False, queue="notify")
 
     return jsonify({}), 204