By Andrea Shalal and Karin Strohecker WASHINGTON (Reuters) -Top U.S. and Chinese officials will join Wednesday's meeting of the Global Sovereign Debt Roundtable, where a key topic will be the lack of transparency about bank loans that have complicated developing countries' debt restructuring efforts. International Monetary Fund strategy chief Ceyla Pazarbasioglu said the continued participation of the world's two largest economies in the roundtable, despite a fierce trade war dividing them, showed their ...