Exclude attachables without content_ids from accessible request form link
Exclude attachables without content_ids from accessible request form link

ConsultationOutcomes are not able to access their consultation's
content_id at the time of building the attachment html.
While this is resolved, to prevent errors any attachables without access to
the content_id will be excluded from the pilot scheme.

alphagov/whitehall,alphagov/whitehall,alphagov/whitehall,alphagov/whitehall