Italian beauty Sara Leonardi   CRICKET hero Glenn McGrath has found love again - 18 months after losing his wife Jane to breast cancer.   The father of two has fallen for Italian beauty Sara Leonardi, a 28-year-old he met while overseas late last year.   "Glenn is happy for people to know he has a girlfriend," his agent Warren Craig said yesterday. "He's happy and so are his children."   McGrath, who turns 40 next week, was photographed for the first time with Sara having dinner in Double Bay on Tuesday evening.   They