BUG: #3257 update color selection when color node changes in Editor

Be sure to use the up-to-date color node to display the names
and colors for the label layer.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22244 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: avoid duplicated saveState when using applyScopedLabel in editor

Since the Chagne and Save island effects use the superclass's
applyScopedLabel method they don't need to explicitly save state
(it is done automatically).

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22245 3bd1e089-480b-0410-8dfb-8563597acbee