I upload files on the frontend using AJAX requests to
actionUpload controller. When file is uploaded, I immediately display it using filename returned by controller.
In case if filename conflict, the duplicate file is created, with a name like
something_200518_221543.jpg. How can I retrieve this duplicate filename, so I can display this file too? In control panel, this duplicate filename is somehow appended to the page, but I don't know how - there is no request that returns this new filename from backend.