NEW YORK — In the last months of Ruth Bader Ginsburg’s life, one of the few people who knew how seriously ill the Supreme Court justice had become was her friend, National Public Radio reporter Nina Totenberg.She kept that news largely to herself.The legendary Supreme Court reporter, with a new memoir “Dinners with Ruth” that celebrates that relationship, has thrust herself into a debate over a basic tenet of journalism and recalled the long history of how Washington leaders and their chroniclers co …