Update fulltext search to take care of private bookmarks

this setup is the same across tests. Let's move this into a common helper like the _get_good_request that sets up both users and their bookmarks. Then the tests are just about the checks. I'd rename the url_one and url_two to be more like:

    admin_public_url = ...
    admin_private_url = ...
    user_public_url = ...
    user_private_url = ...

And then the tests will read nice and clear that we assert we have admin's public and private url and user's public url, etc.