0021096: EDF 1729 SMESH: Create a Projection 1D-2D algorithm

0021096: EDF 1729 SMESH: Create a Projection 1D-2D algorithm

+  static TopoDS_Shape GetCommonAncestor(const TopoDS_Shape& shape1,
+                                        const TopoDS_Shape& shape2,
+                                        const SMESH_Mesh&   mesh,
+                                        TopAbs_ShapeEnum    ancestorType);

+  std::pair<int, TopAbs_ShapeEnum> GetMediumPos(const SMDS_MeshNode* n1,
+                                                const SMDS_MeshNode* n2);