BOSTON – It’s a fabulous all-female Fourth of July celebration in Boston this year.Popstar and Newton native Rachel Platten is one of five women joining conductor Keith Lockhart and the Boston Pops for the traditional concert and fireworks spectacular on the Charles River Esplanade.Amy Ray and Emily Saliers of the folk-duo Indigo Girls, and Rhiannon Giddens, frontwoman of the Grammy-winning Carolina Chocolate Drops, also will share the stage on Independence Day.