Something of an anomaly in the age of multi-screen households and fragmented viewing, the genuine all-ages family movie gets a canny but uncynical revival in “ The Sheep Detectives .” As bracingly odd a proposition to hit the multiplex as any we’ve seen in the last couple of years, the first live-action feature from long-serving Illumination director Kyle Balda (“Despicable Me 3,” “Minions: The Rise of Gru”) is a shaggy hybrid of creature feature and murder mystery that — minus the zippy