Debuting this week on HBO, “The Gilded Age” is a new series from celebrated writer Julian Fellowes. Known for creating the smash hit series “Downton Abbey,” Fellowes has a signature perspective, looking at class, culture, money and power through an “upstairs downstairs” lens. In “The Gilded Age,” he hops across the pond from jolly old England, turning his pen toward the burgeoning metropolis of New York City in 1882, which offers the chance to examine a society with an entirely different class structure. In “The Gilded Age,” there’s a divide between new money and old money, with the added laye…