Opioid addiction is a tough enemy to fight, but public officials are hoping for a growing army of private-sector allies in the battle as a new group seeks to raise $50 million to address the problem. The launch of RIZE Massachusetts drew a mix of business leaders, elected officials and health care professionals to the Taj Boston hotel on Tuesday morning to rally behind the cause. The first donors include General Electric, Partners HealthCare, and Blue Cross Blue Shield of Massachusetts.