Enough is enough. Lower East Side residents aren’t the only ones ticked off at the influx of junkies and vagrants at a popular local park — neighborhood storeowners say the bums are robbing them blind. The gripes come after The Post reported recently that hordes of addicts who were booted from Washington Square Park have found a new home at Sara D. Roosevelt Park smack in the middle of a neighborhood teaming with young families — and hardworking merchants. “Sometimes it’s like a parade,” a