BUG: fix force color to children checkbox in Models

When converting the model displayable manager to use
more scalar options, missed using the hierarchy display node
for cases when it over rides the model display node. Cast
the hierarchy display node to a model node and use it if defined.

Issue #3784


git-svn-id: http://svn.slicer.org/Slicer4/trunk@23549 3bd1e089-480b-0410-8dfb-8563597acbee