From pop stars to popcorn – to the world’s most expensive milkshake – as it gears up to welcome a whole host of events to celebrate it twentieth anniversary this month (August), it’s safe to say the Red Dragon Centre in Cardiff Bay has had quite an eventful two decades!   August 1997 – Will Smith and Puff Daddy both hit number one in the charts – Men in Black and I’ll Be Missing You were surely songs of the…