ENH: Associate icon with the new Slice view layouts

This is a follow-up of previous commit r22385

See #2384

From: Andrey Fedorov <fedorov@bwh.harvard.edu>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22386 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Fix unused variable warning in qSlicerViewControllersModuleWidget

From: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22387 3bd1e089-480b-0410-8dfb-8563597acbee