0021375: EDF 1671 SMESH: Dump study of current state

0021375: EDF 1671 SMESH: Dump study of current state
     avoid crash at deletion of SMESH_subMesh::myOwnListeners at mesh removal

-  std::list< std::pair< SMESH_subMesh*, EventListener* > > myOwnListeners;
+  struct OwnListenerData {
+    ...
+  };
+  std::list< OwnListenerData > myOwnListeners;