LONDON — The line to pay respects to Queen Elizabeth II as she lies in state at Westminster Hall ahead of Monday’s state funeral stretches for miles through central London, snaking south across the Thames River to near Blackfriars Bridge — a distance of some two miles, as of 6 a.m. In typical British fashion, the line, dubbed “The Queue,” is carefully managed, with stewards, wristbands and toilets along the way.