Update func_button flags for radiant
Update for radiant entity description after:
https://gitlab.com/xonotic/xonotic-data.pk3dir/merge_requests/481
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Update for radiant entity description after:
https://gitlab.com/xonotic/xonotic-data.pk3dir/merge_requests/481