Enable File Upload for Reviews With No Previous File Upload

Is your feature request related to a problem? Please describe.
When viewing a completed review, Editors have the option to replace the file the reviewer uploaded. But if the Reviewer did not upload a file, the Review File section of the View Review page does not display. In the event the Editor wants to attach a file to a review in this state (e.g. when a Reviewer emails the file to the Editor rather than uploading it via the form), they are unable to do so.

Describe the solution you'd like
Render Review File section on the View Review page, even if no file is present. Indicate that no file is present and present the Editor with the option to upload one.

Describe alternatives you've considered
We thought to work around this by introducing a new File Upload custom field, but apparently that does not work right now. Having two separate upload fields for the same purpose would also likely cause user confusion.

Start from the View Review page and its existing Review File section, then trace the current editor file-replacement upload flow. Confirm how reviews with no uploaded file are handled and identify the related tests or entry points. Done means the section appears without a file, clearly indicates that state, and lets an Editor upload one.