LONDON — The U.K government has published the first tranche of its long-awaited files relating to the appointment of former U.S. ambassador Peter Mandelson following the revelations about his association with the financier and sex offender Jeffrey Epstein. Mandelson was sacked as Britain’s top Washington diplomat in September last year, with further revelations prompting a police investigation into his conduct which led to his arrest last month. He has not been charged, and his lawyers have