By Huw Jones LONDON (Reuters) – Britain set out long-awaited plans on Tuesday for a new accounting watchdog to shake up the audit market four years after the collapse of builder Carillion undermined investor trust in company balance sheets. The government said it would propose draft legislation to rebuild trust in audit, company reporting and corporate governance by increasing choice in a market dominated by EY, KPMG, PwC and Deloitte, known as the “Big Four”. After Carillion, where 7,000 suppliers and contractors were hit, three government-backed reviews recommended reforms, including replaci…