* Refactor details known to reuse pages and questions
* Refactor page_depends_on
* Use field_for_person
* feat: tweak person_known behaviour to only show for people 2-4, and ask person_known regardless of answer to previous person_known questions. Also remove redundant personx_known files
* test: update tests
* feat: add person 1 known page back in
Co-authored-by: natdeanlewissoftwire <nat.dean-lewis@softwire.com>