By Toby Cudworth Manchester United and Liverpool renew their rivalry on Sunday looking to book their place in the FA Cup semi-finals at Wembley. The balance of power has shifted in the north west since Sir Alex Ferguson’s retirement in 2013, with Liverpool now seen as the dominant force in a rivalry both sides are determined to come out on top of. The Reds are on course for an unprecedented quadruple and have already ticked off the first major trophy of the season – they beat Chelsea thanks to Virgil van Dijk’s late header to lift the Carabao Cup – and are well placed in the Premier League and…