Uma Thurman celebrated her engagement to Arpad Busson with a star-studded party on Tuesday night. Guests including Elizabeth Hurley & husband Arun Nayer, Elton John & partner David Furnish, Sting & wife Trudie Styler, Bob Geldof, Stella McCartney, Claudia Schiffer, Topshop owner Philip Green and artist Damien Hirst were invited…