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/Measure/Gui/TaskMeasure.cpp

@@ -249,7 +249,7 @@ void TaskMeasure::update()
         App::DocumentObject* sub = ob->getSubObject(sel.SubName);
 
         // Resolve App::Link
-        if (auto link = Base::freecad_dynamic_cast<App::Link>(sub)) {
+        if (auto link = freecad_cast<App::Link>(sub)) {
             sub = link->getLinkedObject(true);
         }