Unscripted TV’s ubiquity means a person doesn’t need to have seen a single episode of “Vanderpump Rules” to understand why casting Tom Sandoval in Season 3 of “The Traitors” is an evil genius move. But his very public loss of esteem is the “Traitors” audience’s gain since its divinely clever host Alan Cumming can’t resist taking a swipe. “Traitors” may …
