New Jersey tax revenue is up slightly, state treasury officials reported Tuesday, a change trumpeted by Democrats as a sign of fiscal responsibility as Republicans warned the state is headed toward a fiscal cliff and can’t sustain Gov. Phil Murphy’s long-term budget goals. At the same time, the head of the state Senate Budget Committee floated the idea of raising the state sales tax to 7% rather than passing tax hikes on corporations that Murphy proposed to fund a cash-strapped NJ Transit. State Treasurer Elizabeth Muoio’s appearance before the Senate committee at the Statehouse in Trenton is …