Rebecca Rubin Film and Media ReporterFor anyone who’s been to a shiva, a Jewish mourning ritual, the anxiety-laced comedy “Shiva Baby” feels instantly recognizable: the lox, bagels and rugelach are as plentiful as the overly inquisitive relatives.“Shiva Baby” takes the mishegas up a notch. The film follows Danielle (Rachel Sennott), a college senior accompanying her parents to a shiva.