Rashida Jones ("The Social Network") was funny when she appeared on shows like “The Office” and “Parks and Recreation.” I had to keep reminding myself of this when I discovered her in her first starring role in “Celeste and Jesse Forever” (Jones co-wrote the screenplay in collaboration with Will McCormack), a movie like “(500) Days of Summer” although not as good. Jones plays Celeste to Andy Samberg’s Jesse. Together they form a young