A beautiful and kind woman who improves everything she touches, “Marriage Story’s” Nicole (Scarlett Johansson) appears to be the perfect wife and mother.Once the star of a risque summer teen flick, Nicole gave up her nascent film and television career in Los Angeles to accommodate the aspirations of her off-Broadway theater director husband, Charlie (Adam Driver).Time has passed, and she’s unhappy with the way things have turned out. “I got smaller,” she laments.With his gangly authority …