Meet Eunisses Hernandez — the progressive, permissive councilwoman raking in far more money than the average Angeleno each year, plus gold-plated benefits — even as MacArthur Park, the historic heart of her district, rots into a fentanyl-soaked nightmare. The Post spent the last week inside the park, witnessing and reporting on open-air drug use, pipe smoking, hand-to-hand deals and city-funded paraphernalia — needles, crack pipes and food…