FileUpload: show File page instead of binary file

Summary:
This modification improves a single link shown to the user.

The goal is to make it easier to change file permissions or
file name or whatever just after the upload of the file itself.

Before this change, doing that was difficult because clicking
on the popup would send you back to the binary file only.

Closes T15165

Test Plan:

• upload a file using drag & drop (for example in a comment)
• click on the popup's link
• you see the File page, not the binary file

Reviewers: O1 Blessed Committers, avivey

Reviewed By: O1 Blessed Committers, avivey

Subscribers: avivey, speck, tobiaswiese, Matthew, Cigaryno

Maniphest Tasks: T15165

Differential Revision: https://we.phorge.it/D25074