It's clear that Apple's never going to grow as fast as it has — but it's unclear what the next five years hold for the company, Toni Sacconaghi, analyst at Sanford C. Bernstein, told CNBC's "Fast Money: Halftime Report." Sacconaghi reiterated his position on Friday that "Apple's best days are behind it," which he first told CNBC in 2015. "There's no...