This commit adds the `include_jobs` filter to the
`GET /services/…/notifications` endpoint. It defaults to `True` (ie show
all notifications) but makes it possible to only return notifications
created by _any_ API key.
This is so that we can show a log of all notifications sent through the
API in the admin app.
It does not expose this list to the public `GET /notifications` endpoint
because this would violate our rules about keys only being able to get
notifications created with keys of the same type.