LONDON — Britain and its royal family absorbed the tremors Monday from a sensational television interview with Prince Harry and Meghan, in which the couple said they encountered racist attitudes and a lack of support that drove the duchess to thoughts of suicide.In a two-hour soul-baring interview by Oprah Winfrey, the couple painted a deeply unflattering picture of life inside the royal household, depicting a cold, uncaring institution that they had to flee to save their lives.