Chicago 14th Ward Ald. Edward M. Burke was charged in a criminal complaint unsealed Thursday, with one count of attempted extortion for allegedly trying to shake down a fast-food chain.The federal complaint alleges Burke corruptly used his position to try to drum up business for his law firm, Klafter & Burke, which handles property tax assessment cases.Burke solicited business in return for supporting the chain’s request for permission to remodel a restaurant in his Southwest Side ward, the complaint maintains …