By Laura Armstrong The Beckhams are planning a four day extravaganza to celebrate Victoria’s 50th birthday – but it will not feature a Spice Girls performance. Guests invited to the lavish do have now received save the date cards for the celebrations. And sources told how fashion designer Victoria, who turns 50 on Wednesday, was hoping to reunite with her bandmates during the party. But the plan has since been ruled out. One source said: “David and Victoria have made it known they are planning a party to remember – but now it turns out it will be four nights to remember for members of their fa…