In “Maestro” and “The Killer,” the characters played by Carey Mulligan and Michael Fassbender exist in different worlds. Mulligan’s Felicia Montealegre Bernstein, an up-and-coming actress who becomes conductor Leonard Bernstein’s wife and soul mate, breathes rarefied air among East Coast artists from the 1950s through the ’70s. Fassbender’s tightly coiled, mostly silent assassin, meanwhile, travels […]