Will nobody but Julian Fellowes think of history’s obscenely rich and their wants and needs? With his new HBO series “The Gilded Age,” set in 1882 New York, the creator of “Downton Abbey” is bravely leading the mildewed charge back to days gone by, when robber barons papered over their exploitations with an elegant, high society-minded facade and everyone else knew their place. Truly, what would fair-minded people do without Fellowes here to remind us that the whims of the wealthy should be portrayed as prettily and sympathetically as possible — why do pedestals exist if not to elevate the eli…