LONDON — The former Prince Andrew was arrested by British police Thursday on suspicion of misconduct in public office related to his links to Jeffrey Epstein, an extraordinary move in a country where authorities once sought to shield the royal family from embarrassment. It was the first time in nearly four centuries that a senior British royal was placed under arrest, and it underscored how deference to the monarchy has eroded in recent years. King Charles III, whose late mother lived by the motto “never complain, never explain,” took the unusual...