Base: Rename Base::freecad_dynamic_cast into freecad_cast

This is to make it shorter and easier to use. QT does the same thing
with their qobject_cast.

src/Mod/Import/App/ImportOCAF2.cpp

@@ -478,8 +478,7 @@ bool ImportOCAF2::createGroup(App::Document* doc,
             auto link = doc->addObject<App::Link>("Link");
             link->Label.setValue(child->Label.getValue());
             link->setLink(-1, child);
-            auto pla = Base::freecad_dynamic_cast<App::PropertyPlacement>(
-                child->getPropertyByName("Placement"));
+            auto pla = freecad_cast<App::PropertyPlacement>(child->getPropertyByName("Placement"));
             if (pla) {
                 link->Placement.setValue(pla->getValue());
             }