LAS VEGAS — The bankruptcy of Caesars Entertainment Corp.’s debt-heavy subsidiary has racked up nearly $47 million in professional fees and expenses in about 4½ months.The Associated Press reviewed billings from 18 law firms, financial advisers, consultants and the casino company’s creditors between Jan. 15 and May 31, including one from a law firm that noted it cost $16,367 to prepare its own bill.Another firm’s invoice includes billing for a paralegal who earned $133,490 in that time.And …