Show search terms on search results page

[danielnaab]

Description

As a user viewing search results, I would like to clearly see the search terms I entered in the search results, to help me maintain context.

Notes

We tried to prefill the search box input with the current search terms as part of #736, but encountered some issues with the behavior of accessible-autocomplete. This PR, when merged, should address the problem: alphagov/accessible-autocomplete#425

Acceptance Criteria

• Search query visible in search box when displaying results

Tasks

• PO approved
• Usability tested

Definition of Done

• Pull requests meet technical definition of done
• Code is properly styled per USWDS
• Finished design has been compared against mockup
• Documentation is complete
• CircleCI tests have passed
• Automated accessibility scans have passed
• Manual accessibility testing completed
• Code has been successfully built and deployed into a staging (dev) environment

[brandocalrissian]

Blocked on bug w/autocomplete widget (see notes above)

[brandocalrissian]

related to #737

[brandocalrissian]

Same bug is here.

[brandocalrissian]

Don't do anything on this until a proposal for changing search is denied. Only relevant if staying on search.gov.