Frontend: Add "Product research and feedback" page to user settings
Created by: quinnkeast
Part of implementing RFC 215: Improving User Feedback.
Description
Add "Product research and feedback" page to user settings.
Button link will likely need to support dynamic URL parameters so we can pre-populate a signup form on an external source (e.g. Airtable, HubSpot – yet to be finalized).
Note that based on @dadlerj's feedback, site admins will need to be able to disable this page for all users on their instance (#17647 (closed)).
Design documentation: