By William James and Alistair Smout LONDON (Reuters) -British Prime Minister Boris Johnson bowed out of his final showpiece parliamentary appearance with a round of applause from his party, jeers from opponents and an enigmatic exit line: “Mission largely accomplished … hasta la vista, baby.” Johnson was forced to announce his resignation earlier this month after a mass rebellion against the latest in a string of scandals that his party decided had undermined his ability to lead the country any longer after three turbulent years in charge. Speaking in his final “Prime Minister’s Questions”, …