WASHINGTON — Supreme Court Justice Ketanji Brown Jackson called herself a “Survivor superfan” on Saturday and offered an audience of graduating law school students lessons from the reality TV show.The show has been on television for 23 years and is now in its 44th season. Jackson said she has seen every episode since the show’s second season.“I watch it with my husband and my daughters even now, which I will admit it’s not easy to do with the demands of my day job. But you have to set …