By Sarah Lumley Sunderland has been crowned the side hustle capital of the UK, according to research. The study, of 2,000 adults who make cash in addition to their day job, revealed those up north seem to have more of an entrepreneurial flare, with residents having an average of four side hustles each. But second on the list was London, with people making extra cash typically doing so from two ventures. Ways of making money on the side vary from city to city – with those in Coventry most likely to sell old belongings online, while Stoke resident turn to baking. While those in Sunderland are mo…