[MGTL] Pass element's id to created boundary elems

This ensures correct bulk_node_ids map

MeshGeoToolsLib/BoundaryElementsAlongPolyline.cpp

@@ -80,14 +80,14 @@ MeshLib::Element* modifyEdgeNodeOrdering(
         {
             std::array nodes = {const_cast<MeshLib::Node*>(e->getNode(1)),
                                 const_cast<MeshLib::Node*>(e->getNode(0))};
-            return new MeshLib::Line(nodes);
+            return new MeshLib::Line(nodes, e->getID());
         }
         if (auto const* e = dynamic_cast<MeshLib::Line3 const*>(&edge))
         {
             std::array nodes = {const_cast<MeshLib::Node*>(e->getNode(1)),
                                 const_cast<MeshLib::Node*>(e->getNode(0)),
                                 const_cast<MeshLib::Node*>(e->getNode(2))};
-            return new MeshLib::Line3(nodes);
+            return new MeshLib::Line3(nodes, e->getID());
         }
         OGS_FATAL("Not implemented for element type {:s}", typeid(edge).name());
     }