SAN DIEGO — The state of California is wading into a 20-year legal dispute over ownership of a French Impressionist painting taken by the Nazis during World War II from a Jewish woman whose heirs settled in La Mesa. In a motion announced Thursday, the Attorney General’s Office asked for permission to file a “friend of the court” brief that argues in favor of giving the painting, now hanging in a Spanish museum, to the Cassirer family. “California has long asserted its strong interest in seeking justice for art theft victims,” the state wrote. The paperwork was filed with the...