NEW YORK -- The weekend at movie theaters featured something not seen for a while: a genuine box-office battle.Warner Bros.' “Mortal Kombat” reboot and the Japanese anime film “Demon Slayer: Mugen Train” both vied for the top spot at the North American box office, with “Mortal Kombat” narrowly edging “Demon Slayer." The R-rated “Mortal Kombat” earned an estimated $22.5 million, according to studio estimates, while Funimation's “Demon Slayer” grossed $19.5 million.The two releases fueled the best