Link to notification from API integration

It’s useful to be able to see what the email or text message looks like,
especially if you’ve sent it with a test API key (so it isn’t in your
inbox or on your phone). We already have the page for this, so we just
need to link to it.

tests/conftest.py

@@ -1856,7 +1856,7 @@ def mock_get_notifications(
         job = None
         if job_id is not None:
             job = job_json(service_id, api_user_active, job_id=job_id)
-        if template_type:
+        if diff_template_type or template_type:
             template = template_json(
                 service_id,
                 id_=str(generate_uuid()),