Bargain Booze owner Conviviality Retail has raided rival Musgrave to appoint a new chief financial officer. Julie Wirth has been finance director at Musgrave, which runs rival convenience store chains Budgens and Londis, since 2008. But she will move to Conviviality, which also runs the Select Convenience and Thorougoods chains, on November 4. The appointment comes days after the business was floated on the Alternative…