Like many others clad in orange and black around her, Cheryl Shawl, 60, had been waiting since dawn today through waves of rain to see her heroes: the Giants. And when the World Series championship parade finally started rolling down Market Street around noon, Shawl and the rest of the dense crowd went wild. Players, celebrating the third trophy in San Francisco in the past five years, towered above the crowd on double-decker buses, waving…