Director Tony Goldwyn opens his family dramedy “Ezra” in the warm, collegial comfort of a comedy club. Max (Bobby Cannavale) perches on a stool, a handheld camera drifting closer and closer as he tells jokes about his life, including his autistic son, layering truths with punchlines, walking a tight-rope of tones. It’s an invitation from Goldwyn, and screenwriter Tony Spiridakis, to sit down and listen awhile as they unfurl this heartfelt, humorous and sometimes harrowing yarn.