A heartless home health aide and her family allegedly commandeered a patient’s Upper East Side apartment, refusing to let her daughter in after the 103-year-old woman’s death — and cruelly threatening to flush the old lady’s ashes down the toilet if she tried, according to court records. Incredibly, the alleged squatters claim they have “succession rights” to the East 86th Street pad because they were like “family” to the dying woman, according to court papers. Tatiana Abello, her mother, and sister have been living in the $ 2,088-a-month, two-bedroom, rent-stabilized pad for 18 months and counting since their elderly charge,...