Describe the new feature:

osu!stable has the (secret?) ability to screenshot and directly upload the screenshot on internet with the keybinding Shift+F12 and this feature is quite convenient when sharing screenshots of scores in the game chat / on any messaging app (discord). This basically asks for porting this feature to lazer.

Proposal designs of the feature:

The keybind could be added back to lazer along with the feature. To allow a use on mobile aswell, we could probably add a "share" button on the results screen (possibly on the score card?) that would screenshot and upload it, and do whatever action appropriated to the platform with the screenshot url.

Since osu!web now got a page to see individual scores, the share button could alternatively copy to clipboard / chat the online score url, given that the score was submitted.