Regression of XSMESH_TEST/SMESHCOMMON/SMESH_TEST/Grids/smesh/bugs12/M6

Fix the ensuring stability of SMESH_MeshEditor::makeWalls(). Allow
storing both nodes and cells in one map sorted by ID.

struct TIDCompare {
   bool operator () (const SMDS_MeshElement* e1, const SMDS_MeshElement* e2) const
-  { return e1->GetID() < e2->GetID(); }
+  { return e1->GetType() == e2->GetType() ? e1->GetID() < e2->GetID() : e1->GetType() < e2->GetType(); }