Formats/File needs a Side Peak mode

For inspecting the images that appear under "Files" in "Formats", it would be useful to have a Side Peak mode.

I have already a lot duplicates there because of repeatedly pasting random stuff.
The light table, aka image viewer, is nice, but it is not enough to decide which images can become deleted.
(I'll write a separate request for the image viewer btw.)

The Collection (or whatever Formats/Files is called) shows more context information then the viewer, but it would be nice to see the image at the same time, in a Side Peak.