Sidecar category filter

[jadO]

In the sidecate category filter the number behind each category should reflect the actual possible number of combinations.
This would be most useful for combining different categories via "all".

Otherwise with a lot of categories I have no idea which categoriy combination will deliver results and which won't thus I have to try on a try and error basis.

Example:

Category1(10)
Category2(20)
Category3(30)
Category4(40)

Now when I select Category1 with "all" then it should update to reflect the number of possible matches:

Category1(10)
Category2(0)
Category3(7)
Category4(25)

This way I can see immediately that I don't have to try combining category 1 with category2 because it would produce a 0 match. But with category 4 it would be matching 25 files.