Improve filtering/searching for Rules [#2052321]

Personally, I must say I dislike that I always have to open the filters fieldgroup before can I go ahead filtering. Having something that does not take much space but is always open would be probably better.
Supporting search for categories would be useful to e.g. find all rules related to "paypal". See #2052317: Support rule / action / event / condition categories in addition to groups.
Text-based search: https://groups.drupal.org/node/290888#comment-946668 - is that feasible, important?
Should we make filters to persist in the session?