In “Shazam!,” Zachary Levi brings off something so winning it’s irresistible. He plays a square-jawed, rippling-muscled man of might, with a cheesy Day-Glo lighting bolt affixed to his chest, who projects an insanely wholesome and old-fashioned idea of what a superhero can be. But he’s also playing a breathless teenage kid on the inside, and […]