Oh, man, when I fall into the CanLit tree, sometimes I manage to hit every branch on the way down. I say I like character-driven stories, but Garbo Laughs is a harsh reminder of how important plot is even when your character drives things. Because in this case, Elizabeth Hay’s characters aren’t driving the story, so much as sitting around while a narrative just kind of tumbles desultorily around them, tugging at them occasionally in…