ALUN JOHN, SUMEET CHATTERJEE and  LAWRENCE WHITE  GLOBAL banks faced a fresh scandal about dirty money as they sought to limit the fallout from a cache of leaked documents showing they transferred more than $2 trillion in suspect funds over nearly two decades. Britain-based HSBC, Standard Chartered and Barclays, Germany's Deutsche Bank and Commerzbank, and JPMorgan Chase & Co and Bank of New York Mellon Corp were among the lenders named in the report by the International Consortium of Investigative Journalists and based on leaked documents obtained by BuzzFeed News. While some banks said many of the transactions happened a…