Bug: Clicking back to an empty search dead end's with an incorrect error

[bmtcril]

Repro:

1. Go to course catalog
2. Search for something that doesn't exist
3. The course cards don't clear, so click one to view course details
4. Click the back button

Or just go directly to a URL with a search query param that yields no results (ex: http://apps.local.openedx.io/catalog/courses?search_query=asdasda ).

In either case the search and filter UI are missing, and the incorrect error block "No courses available" is displayed. With no UI to continue, the user is forced to go back to top nav to return to the catalog.

Kooha-2026-08-31-11-01-29.webm

[bmtcril]

Found in end-to-end testing, issue to re-enable related tests once this is fixed is here: openedx/end-to-end-tests#28