By Marc Jones LONDON, Jan 16 (Reuters) - Transactions on a new China-led digital currency platform have surged to over $55 billion, a new report shows, the latest sign that efforts to build alternatives to ​dollar-dependent global payment systems are gaining traction. Data crunched by the Washington-based Atlantic Council showed the prototype 'mBridge' ‌platform, which is being tested by central banks in China, Hong Kong, Thailand, the United Arab Emirates and Saudi Arabia, had now processed more ‌than 4 ...