Paste rnd openedviewer dev5 0

see https://trac.openmicroscopy.org.uk/ome/ticket/7303

To Test:
 * Import  twice the same image
 * Open one image in Full Viewer.
 * Turn off one channel for example. Save. and keep the viewer opened
 * Go to the data manager.
 * Select the image not opened. Right-click and select Rendering Settings >Copy rnd
 * Select in the data manager, the image opened. Right-click and select Rendering Settings >Paste rnd.
 * Thumbnail should be updated, image in the viewer should be updated.
 * Close the viewer. The save dialog should not be displayed.

Second  test
However when the first image (the one that was modified and then had settings from second image pasted into it) is subsequently modified and the changes saved, it should not just revert to the pasted settings every time. 


--rebased-from #1992