BUG: Set slice plane coordinates using plane source filter

Triggering ModifiedEvent on the input polydata does not (yet) propagate
onto the model node.
Closes #3780

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23523 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Propagate ModifiedEvent to volume/modelNode

When setting a raw (vs pipeline filter) input data to a mrml node,
the node was not notified (ProcessMRMLEvents) whenever the data
was changed because the trivial producer internally used
is not forwarding events.

Issue #3780

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23524 3bd1e089-480b-0410-8dfb-8563597acbee