Unforgettable is a pulpy crazy-ex thriller about the resentment directed at someone taking up space where they do not belong. Rosario Dawson is the likeable new squeeze and Katherine Heigl is the ice-Barbie hovering at the sidelines, desperate and calculated, willing to do anything to reclaim the family she believes to be rightfully hers. And the movie itself, a first time directorial effort from seasoned producer Denise Di Novi, feels like it has taken a swerve and ended up in the wrong place. Sitting in the multiplex, you feel like you’ve drifted off on the sofa watching middle of the…