TRENTON, N.J. — Republican Gov. Chris Christie and the state’s Democrat-controlled legislature must find $1.57 billion to put into pension funds for retired public workers, a judge ruled Monday in a decision that comes as a major legal blow to the governor as he prepares to run for president. Unions for public workers sued Christie after he announced last year he would not make the full pension payments he had agreed to in a 2011 overhaul that was one of his main accomplishments. Superior Court Judge …