Kraft Heinz Co. said Tuesday it plans to split into two separate companies, undoing a mega-deal ushered in a decade ago that turned the maker of Kraft Mac & Cheese into one of the largest packaged food sellers in the world. Following the breakup, one company will be made up of its Heinz Ketchup and other iconic condiments and boxed meals — a unit that currently generates $15.4 billion in sales. The second firm will include the slower-growing grocery products such as Oscar Mayer hot dogs and