The saddest thing about the "The Great Russian Nutcracker" performance Wednesday at George Mason University wasn't the ironic name, or the sparsely sold orchestra seats, or the unÂdeserved standing ovation. No, the saddest thing was the sold-out balcony. Presumably, middle-class families bought tickets hoping for a good value in holiday entertainment. What they got can't even be called a cheap thrill. The Moscow B…