This boxy computer-animated adaptation of the “Clone Wars” videogame is all battle and no myth, and overarching myth is what drove the Star Wars franchise. The action scenes should be the picture’s calling card, yet most are noisy and relentless, full of charging armies making advances, then falling back and vice versa. If it weren’t for the laser cannons and light sabers, you might think you were watching Gettysburg (which is also a video game, by the way).