The way attachments were listed in the admin site was very difficult to use. The `file` field was linking to the download URL, and the only other link to the change page was the caption, which could be empty. This change improves the admin list so that the filename rather than the path is listed (potentially cropped to preserve the page with), but that always links to the change page. The "Review Request ID" column now properly shows the linked review request even when the attachment is part of a draft or in the inactive list. A new column has been added with the download link. Testing Done: Used the admin list and was actually able to get to the change page for many of my attachments.