Allow reordering files uploaded on the feedback site

When I make a comment or report with screenshots presenting some flow on the site, I'd like them to be consistent with the order of operations in that flow. Currently, that can be a challenge since the order seems to be entirely based on whatever order the browser gave the files in. As an example, when I uploaded screenshots in https://feedback.fluxer.com/p/3545/c/8260, they ordered in completely reverse order to what I would want them to be in (presumably because my file picker had them sorted in descending order by date rather than ascending and I simply shift-selected multiple images).

Allow reordering the files in the report.