Keep filters on reload and page change

In the previous version of the system the filters for lists (keyword) remained active when a page was reloaded or if you left a page and returned later. Users in Cologne were asking to bring that back and I agree that it would be much more convenient. This applies to all filters (not only keyword) and also to the filter for the annotation list in the post annotator.

Linked to: #2061 (closed)