Talk about a fish tale. In a turbulent shake-up of New York’s ultra-luxe sushi scene, Midtown newcomer Sushi Sho has managed to snag a coveted three Michelin stars — overturning the proverbial boat of longtime Columbus Circle three-starrer Masa, which was downgraded to two after holding the top rating since 2008. The Bryant Park–adjacent counter, which opened quietly last year with little media attention and even less signage, is now officially the most powerful piece of fish in town, where