Sebastian Stan may still have one foot in the superhero industrial complex of “Avengers: Doomsday” and “The Batman: Part II,” but the actor is increasingly building the other side of his career around international auteurs. After working with Romanian filmmaker Cristian Mungiu on the Palme d’Or-winning “Fjord,” Stan now says he wants to focus his attention on Europe. “My sights are set on Europe now,” Stan told French outlet Le Journal du Dimanc…