WHEN John Mayer was snapped having lunch with Mandy Moore at La Esquina on Tuesday, it sparked rumors of a love match between them. But Mayer has his sights set on a more glamorous Hollywood gal - Cameron Diaz . The same day, Mayer took Diaz to an intimate, late-night dinner at Lafayette Street eatery Indochine. “They were very playful and cozy,” said a fellow patron, who reports they ordered cocktails and “lingered over dessert.” Mayer, 29, and Diaz, 34, ...