Desktop->Right-click Paste to New Window loses annotation and hidden region data

Jalview has an internal clipboard which allows copy/paste between alignment windows to preserve annotation, hidden regions and dataset references.

This clipboard is not checked when copying a region in an alignment window, and then right-clicking on the desktop background to bring up the Paste to New window option, so any hidden regions/annotation/refs are lost in the new window.

To reproduce, hide a region in a sequence, copy the whole alignment to the clipboard, and use the right-click popup menu on the desktop background to paste to a new window.