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/PartDesign/App/Body.cpp

@@ -194,7 +194,7 @@ bool Body::isSolidFeature(const App::DocumentObject *obj)
             // Datum objects are not solid
             return false;
         }
-        if (auto transFeature = Base::freecad_dynamic_cast<PartDesign::Transformed>(obj)) {
+        if (auto transFeature = freecad_cast<PartDesign::Transformed>(obj)) {
             // Transformed Features inside a MultiTransform are not solid features
             return !transFeature->isMultiTransformChild();
         }