Search pages: multiple searchable fields

[kristinenielsen]

Build plan:

• Add some JS script to the search and results pages (citations & policy-docs) providing a way to add a new search bar with a "field" dropdown
• Rewrite part of the JS table update function to use multiple search inputs instead of one
• Rewrite the initial search (leading to the result page) backend to use multiple search inputs instead of one

Estimate

2 days

Acceptance criteria

• The User can add search boxes to any of the pages allowing search