WASHINGTON — The Supreme Court on Monday wrestled with a nationwide settlement with OxyContin maker Purdue Pharma that would shield members of the Sackler family who own the company from civil lawsuits over the toll of opioids.The justices seemed by turns reluctant to break up an exhaustively negotiated agreement, but also leery of somehow rewarding the Sacklers.The agreement hammered out with state and local governments and victims would provide billions of dollars to combat the opioid epidemic. The Sacklers would …