Search for files in trashbin

[juliusknorr]

For restoring files in the trashbin (especially in groupfolders) it would make sense to perform a search inside of the trashbin if the user has currently opened the trash file list.

[being-peace]

Mostly a duplicate of #24544.
There it has been said that there was some developing activity. So I guess, this can be closed.

[susnux]

This is now possible with #45708