Add enum type generation code to the gir sources. This fixes enum types
showing up as 'undefined' in gjs.

The change did not impact Python.

--✀--
const {Gio, GLib, GnomeBluetooth, GObject} = imports.gi;

client = new GnomeBluetooth.Client();
client.connect('notify', () => {
        print(client.default_adapter_state);
});

ml = new GLib.MainLoop(null, false);
ml.run()
--✀--