Protesters who have been blockading the entrance of Citigroup’s New York City headquarters for more than a month claim they were shoved by one of the banking giant’s top lawyers in a violent scuffle caught on video — but the bank denies any wrongdoing by any of its employees.Shocking footage of the incident obtained by The Post, which has also been circulating in edited form on Instagram, shows a man in a blue, button-down dress shirt and jeans pushing against a line of protesters who are holding what looks ...