Luiz C. Ribeiro for NY Daily News/Tribune News Service via Getty ImagesDonald Trump finally got his long-awaited courtroom showdown with his one-time lawyer Michael Cohen on Tuesday, as the former president made a big show of gawking at his former top aide as Trump’s new favorite attack dog, Alina Habba, went after Cohen for his checkered past.He took the fall for his boss years ago—and Trump wasn’t going to let him forget it.The former president isn’t legally required to attend his own bank fra