By THE PULSE NEWS MEXICO STAFF     Hamburger-lovers take heart: That now-iconic chain of ultra-scrumptious, ultra-high-end, ultra-long-lines-to-get-to burgers that have taken the U.S. carnivorous world by storm is slated to open in Mexico sometime next year. Yes, Shake Shack, home to the best burgers and worst service in the United States, is partnering with Mexico’s Grupo Toks to bring its first not-so-fast-food