Add a way to find filters you are subscribed to

There is currently no way to find the filters that I am subscribed to. If I am subscribed to a filter that was neither created by me nor a favorite of mine then there is really know way to discover that subscription.

A way to do this would be to add a boolean to the "Search Filters" screen for "Subscribed to by me". The search mechanism would also have to resolve subscriptions to groups that I am a member of.