Missing autocompletion fields

This PR will check the presence of certain fields which are marked as machine readable.

I still need to:
- [x] Add serialised field to store metadata fields
- [x] Add response field to store machine readable states
- [x] Compare machine readable states with checkboxes on backend
- [x] Compare machine readable states with checkboxes on autocompletion (frontend)
- [x] Check on autocompletion that the fields are present, otherwise trigger an error (+ minor styling)

The autocompletion javascript has been changed so that radio buttons, checkboxes and select fields are selected by their reference identifier rather than their index. I've tried to check these are correct with all the contextual information, but @JeniT and @pezholio you may want to double check these. Some of these seemed to be 1-indexed and some others to be 0-indexed; while the code always assumed they were 0-indexed.