ENH: add a more realistic and usable scripted module template

Instead of 'dummy' parameters, make the template include node
combo boxes and an apply button.  Also put the Reload and Test
functionality into a collapsible box.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@21714 3bd1e089-480b-0410-8dfb-8563597acbee