Add default search for BrowseViews

[saemideluxe]

For the person browse overview we use a special SearchBackendConfig. This is good and should not change. However, the bread.views.BrowseView actually supports filtering via a URL parameter ("q" by default). This is currently not used anywhere.

We need to add support so that any browse view can have a simple default search. BrowseView.get_queryset has the filtering via djangoql implemented, this should be reused. We need to implement a configuration parameter so that a default SearchBackendConfig can be used for any view

An example use case would be the report browse view. Right now there is no way to search for the name of a report. After this is implemented, the report view should have a search-bar (via SearchConfigBackend) which allows to search by name. The browse view for reports should only need a small additional parameter to enable that search bar.

Important: This functionality should not use the resultcontainerid of bread.layout.components.search.Search but work via URL-queries and page reloads. It might be a bit challenging to implement this so that both ways work.

[dward2nd]

Done as in this PR #110

[dward2nd]

Moved from Test to Development because I got some comments from @saemideluxe to adjust the BrowseView's search.

[dward2nd]

I have almost completed the default search box for BrowseView. However, I still encounter a problem distinguishing between the general search input box one and one that might appear in other places (like a navigation bar).

[dward2nd]

We can technically apply this solution though it might look ugly in practice. Or maybe we should temporarily remove the default value based on the GET queries.

[saemideluxe]

Okay for now