By Andy Bruce and David Milliken LONDON (Reuters) -The Bank of England sought to quell a fire-storm in Britain’s bond markets, saying it would buy as much government debt as needed to restore order after new Prime Minister Liz Truss’ tax cut plans triggered financial chaos. Having failed to cool the sell-off with verbal interventions over the previous two days, the BoE announced on Wednesday the immediate launch of its emergency bond-buying programme aimed at preventing the market turmoil from spreading. The plan delivered by Truss’s finance minister Kwasi Kwarteng on Friday for tax cuts on to…