WIP default responses attic cleanup

When form not found:

 - if app_settings.forms_only_mode add `form_not_found` error message.
 - if not forms_only_mode add `sms_received` response message.

When form is found:

 - form validation and response messaging happens with app_settings.

When facility is not found:

 - add error facilty_not_found
 - sentinel will try to resolve facility
 - if public_form property is true on form registrations transition will run
   on form and responses can be set there.

Removed following unused translations:

`form_received`
`reporting_unit_not_found`

Removed support for following form properties:

`messages_task`

  - Use app settings; define a form and setup a response.

`autoreply`

  - Use translations on sms_received and form_not_found or use
    settings to define a form and setup a response.

`facility_required`

  - Replaced by `public_form` property on form.

Removed doc.responses legacy property. Use doc.tasks.

Removed updateRelated update function since it's basically dead code, and related tests etc. Sentinel provides this function.

This also fixes #614.

TODO:

Removed following unused settings:

`public_access` (?)

modify sentinel:

 - if public_form is false we set a response

check if views are unused:

  - clinic_by_refid
  - clinic_by_phone
  - clinic_by_parent_phone
  - facility_by_phone