After nearly three decades of eating (and making) shrimp cocktail, I have come to an inescapable conclusion: It is really hard to do better than Heinz cocktail sauce, especially if you add extra horseradish. I’ve tried fancier, more expensive brands of cocktail sauce, and I’ve made my own, but I always return to Heinz, metaphorical hat in hand. (My boyfriend made the mistake of buying the Beaver b