The second chapter in the saga of “John Wick” is a curious beast. In many ways, it feels like the third part of a trilogy rather than the sequel to a surprise break-out hit and it’s in trying to make the leap from one hit wonder to franchise that the film loses its way. Having avenged himself for the theft of his car and the death of his dog, John Wick (Keanu Reeves) has settled back into…