Lust, jealousy, betrayal and murder have always made for potent story-lines and there’s undoubtedly something of the Greek tragedy about George Bizet’s much loved opera, Carmen. Yet despite all the ingredients of a modern-day soap melodrama played out to a stirring musical score – and all condensed into a couple of roller-coaster hours – the National Opera and Ballet Theatre of Moldova’s performance of Carmen comes across as conservative and a little stiff. There’s no doubting the success of award-winning director Ellen Kent, whose colorful staging of the world’s great operas and ballets has been packing them in across the…