Use OCCT Handle macro for Handle_ classes

This is the result of running OCCT's upgrade script provided
with OCCT 7.0. See
https://www.opencascade.com/content/freecad-occt710-and-windows-rtti-data-missing#comment-form
and
https://www.forum.freecadweb.org/viewtopic.php?f=4&t=21405&start=120#p169019
for why this is necessary for OCCT >= 7.1

src/Mod/Part/App/TopoShapeVertexPyImp.cpp

@@ -98,7 +98,7 @@ int TopoShapeVertexPy::PyInit(PyObject* args, PyObject* /*kwd*/)
     if (!success) {
         PyErr_Clear(); // set by PyArg_ParseTuple()
         if (PyArg_ParseTuple(args,"O!",&(PointPy::Type), &object)) {
-            Handle_Geom_CartesianPoint this_point = Handle_Geom_CartesianPoint::DownCast
+            Handle(Geom_CartesianPoint) this_point = Handle(Geom_CartesianPoint)::DownCast
                 (static_cast<PointPy*>(object)->getGeomPointPtr()->handle());
             gp_Pnt pnt = this_point->Pnt();
             x = pnt.X();