Use template_type property directly from API

It’s included in the job/upload response now[1]. So we don’t need to
fetch the template every time we want to access it.

1. https://github.com/alphagov/notifications-api/pull/2728

tests/__init__.py

@@ -354,6 +354,7 @@ def job_json(
     job_id=None,
     template_id=None,
     template_version=1,
+    template_type='sms',
     created_at=None,
     bucket_name='',
     original_file_name="thisisatest.csv",
@@ -375,6 +376,7 @@ def job_json(
         'service': service_id,
         'template': template_id,
         'template_version': template_version,
+        'template_type': template_type,
         'original_file_name': original_file_name,
         'created_at': created_at,
         'notification_count': notification_count,