BUG: Fixed SH node clone bug

Some data role plugins rely on node attributes and/or place in branch to determine whether the data node can be claimed. In such cases, the SH item created by the SH plugin logic could be claimed by a more generic plugin (e.g. RTDose vs Volumes) when adding the cloned node to the scene, but before attributes were copied, or item was placed in branch. By requesting plugin search after these operations, the proper plugin claims the cloned data node

git-svn-id: http://svn.slicer.org/Slicer4/trunk@25856 3bd1e089-480b-0410-8dfb-8563597acbee