[Feature] Add "Duplicate" notification when uploading duplicates from mobile app

[schweppes-0x]

I have searched the existing feature requests to make sure this is not a duplicate request.

• Yes

The feature

As the title suggests, whenever we're uploading a image and it's a duplicate, show some kind of a sign/popup/notification which will dissapear after 1/2 seconds.

Platform

• Server
• Web
• Mobile