The most refreshing thing about Joshua Green’s new book on the president and his alleged archmanipulator is that it belies its own title. “Devil’s Bargain: Steve Bannon, Donald Trump, and the Storming of the Presidency” doesn’t really demonize the White House chief strategist at its center. Delicious from page one, a tad stale down its home stretch, it is a nearly balanced look at the intellectual underpinnings of last year’s electoral revolution, and at a right-wing rebel at the right hand of power — for the moment.