A Star Is Born is unstoppable. It’s got audience affection and Academy respectability in its sights, and it barrels straight at them. Produced, directed, written and starring Bradley Cooper, this is the Hangover star’s leap for high populist acclaim and he doesn’t take any chances, fashioning, alongside brilliant co-star Lady Gaga and mother! DP Matthew Libatique, a swelling, soapy, lens-flare multiplex ballad. While you’re busy tapping your foot, it eats your heart.  A Star Is Born’s primary achievement is how it escapes the orbit of well-thumbed, downright cliched, material through sheer performative will. Cooper is Jackson Maine, a damaged classic rock…