Feature: Show both thumbnails during file conflicts

### What feature or improvement do you think would benefit Files?

If you observe the file conflict window in the standard File Explorer, it shows both the thumbnail of the source file, and destination file. This makes it easy to tell, for example, if two images have the same filename, but are obviously different. This makes checking through the list and choosing which files to skip and which to auto-rename a lot easier. I think it would be very beneficial for Files to adopt a similar layout, instead of only showing the thumbnail of one of the files, and only the filenames of both (not even size!)

### Requirements

- An overhaul of the file conflict window.

### Files Version

3.0.8.0

### Windows Version

10.0.22631.2428

### Comments

_No response_

The issue does not identify files, tests, or an entry point for the file conflict window. Start by locating that window and its existing thumbnail and filename handling; the work is done when both source and destination thumbnails and the requested conflict information are shown in a usable layout.

Written by the indexing model from the issue text.