TRENTON, N.J. — Top U.S. drug wholesaler McKesson agreed Wednesday to create an independent board chairman, responding to a Teamsters-led shareholder protest over its role in distributing opioids. McKesson Corp. is dealing with lawsuits, government investigations and fines for its handling of suspicious opioid orders to U.S. communities. Wholesalers buy drugs from manufacturers and sell them to pharmacies, hospitals and nursing homes. The company’s move came even though shareholders at Wednesday’s meeting didn’t back the Teamsters’ proposal to split the CEO and board chairman jobs to provide more oversight.