Nostalgia as escapism is ubiquitous. But what if nostalgia could be a force for good? Not an inelegant poke in the dopamine receptors, but rather, transcendent, even galvanizing, as it is in the case of Joseph Kosinski’s “Top Gun: Maverick,” a legacy sequel that that allows the viewer to luxuriate in the glorious aura of the original “Top Gun,” while simultaneously reckoning with what Tom Cruise, The Last Great Movie Star, might mean after all these years. Tony Scott’s 1986 “Top Gun” is a visceral experience: all sweat, Venetian blinds, power ballads, roaring jet engines and sunset silhouettes…