"Copy row" - Support multiple items in clipboard

[PeterRygeBestseller]

Right now you can only copy one thing at a time using the "Copy row" button on array fields. Whenever you copy the next thing, the existing item in the clipboard is overwritten.

A nice addition in the future would be to support copying multiple items to the clipboard. Then from a selection menu, choose what to paste from the clipboard. Kind of like in Umbraco: