Race-conscious and class-conscious but with a young, street-smart cast of characters, What We All Long For should have been amazing. It should have deserved every bit that “Globe and Mail Best Book” seal on its cover. Dionne Brand should have wowed me with her portrayal of first-generation Vietnamese Canadian Tuyen versus Tuyen’s immigrant parents and sisters. The troubled relationship between Carla and her kid brother, Jamal, should have opened my eyes to the subtle…