Three decades ago, a prostitute was viewed and convicted as a criminal.Over time, the legal system has recognized many of these women as victims of sex trafficking, and changes in state law provided an avenue to clear prostitution convictions from their records. But other convictions stemming from their prostitution cases were harder to wash away.An order issued by a Cook County judge last month may open more doors for victims to have these convictions vacated.Days before his retirement from the bench, Cook County …