[Sofa.Common] Fix SceneLoaderXML invalid root filename & lineno (#5729)

The XML loader does not properly set the location of the root node, so
using the Go To Scene... in the UX does not work.

The PR fix it.

Author: damienmarchal

Sofa/framework/Simulation/Common/src/sofa/simulation/common/SceneLoaderXML.cpp

@@ -138,6 +138,8 @@ Node::SPtr SceneLoaderXML::processXML(xml::BaseElement* xml, const char *filenam
     }
 
     Node::SPtr root = down_cast<Node> ( baseroot );
+    root->setInstanciationSourceFileName(xml->getSrcFile());
+    root->setInstanciationSourceFilePos(xml->getSrcLine());
 
     return root;
 }