Active explore when clicked

[oveddan]

Changed explore link and header behavior.

• If land on explore page and have not explored yet, show the header, but don't highlight explore.
• Once have done anything (scrolled, clicked, dragged) then collapse header and highlight explore text.
• If navigate back to explore page from a student details page, lets say via clicking on a tag or advisor, then header remains collapsed and explore highlighted.
• If landing on filtered cards, from the outside world directly, then header is expanded and explore not highlighted until an action occurs

Code changes:

• Refactored to match home page by using useRouteMatch.
• Passing that from header to headerbg so that the logic exists in one place
• Once have explored, setExplored to true.
• Moved useClick tracking to its own component, which is done by route (so that clicking doesnt occur when not exploring). Refactored useClicked to clean itself up.