NEW YORK – In a movie year mostly lacking big, ambitious releases, Steve McQueen’s “Small Axe” anthology is an unqualified main event. For the filmmaker of “Hunger,” “Shame” and “Widows,” “Small Axe” is a shattering masterwork — a compendium, both damning and celebratory, of Black resilience. The only fictional tale of the bunch, it brings to vivid, pulsating life a blues party from 1980, when young London Black people found refuge, and love, at house parties. Casting “Small Axe,” he has said, was easy because of all the untapped talent just in need of an opportunity. But if anyone expecting a neat arc to “Small Axe,” McQueen says that’s not its shape.