Favorite queries in Find panel

[humdinger]

This is hrev45646.

I've been thinking on #9780 and remembered an idea I posted about somewhere many years ago. Couldn't find it anymore...

It's about adding favorite query (templates) to the Find panel. I often find it cumbersome to start with an empty find panel and having to choose the filetype I look for and then adding the attributes I want to query etc. I know I can create query templates and start from those instead (and I do), but having some favorites in the find panel directly seems to be a good idea.

Mockup:

This mockup also includes what I commented on in #9780. The "+ / -" buttons are to add another attribute to search under that line or to remove this line, of course.
Additionally, there's a "Favorites" expando view at the bottom, in case someone prefers a maximum clean GUI and doesn't need favorites. (There could be a "Favorites" menu item in the menubar as well, for "purists").

This is how I could imagine it working:
You add the currently constructed query by drag'n'dropping the query symbol from the top into an empty slot below. I used LaunchBox for my mockup, maybe its code can useful as well.
The icon depends on the query's targetted mime type.
If you drop different querys with the same mime-type, like image/png, image/jpeg, image/gif, onto an existing icon of the same supertype, the icon gets an overlay arrow and works like a pop-up menu to access all the favorite queries of that super-type.
Tooltips show details of a favorite, i.e. the searched mime type and attributes, for example:

MPEG audio file
  Artist | Title

You remove an item with a context menu.

The query templates of those favorites can be saved in their respective super-type subfolder under ~/config/settings/Tracker/QueryFavorites

[humdinger]

mockup with expanded favorites