This way we can return a nullptr for cases where the class does not want
to provide a property at all. For example outside of bindings when
reading the default value. The moc-generated code can check for such
nullptrs and handle them.
Change-Id: I7ff478cb254012147bb7aed3feb160e3e679cb6d
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>