Move the feature to corelib so that the QMetaType enumeration
values can be properly excluded and there is no need for a
dummy class.
Use QT_REQUIRE_CONFIG in the headers of classes to be disabled.
Add headers/source files in the .pro file depending on the configure
feature in libraries and tests.
Add the necessary exclusions and use QT_CONFIG.
Task-number: QTBUG-76493
Change-Id: I02499ebee1a3d6d9a1e5afd02517beed5f4536b7
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>
dff3843d98