Gui: Improve transform UI responsivness

This introduces much faster CenterOfMassProvider#supports method that
can be used as cheap pre-check to see if the object supplied could have
the center of mass and so delay the domputation to a moment where it is
actually needed.

src/App/Services.cpp

@@ -27,4 +27,9 @@ std::optional<Base::Vector3d>
 App::NullCenterOfMass::ofDocumentObject([[maybe_unused]] DocumentObject* object) const
 {
     return std::nullopt;
+}
+
+bool App::NullCenterOfMass::supports(DocumentObject* object) const
+{
+    return false;
 }