White picket fences. Sunny skies. Block parties. Nosy neighbors. Little boxes. Mortgages. Ah, the wonders of Suburbia, the one-time dream neighborhoods that have since become symbols of class signaling, domesticity, and getting trapped in a matching McMansion, popping out a couple of kids until your life passes you by and, dear god, we used to have dreams once, Linda! Irish filmmaker Lorcan Finegan captures that existential malaise and panic handily with his new oddball fantasy-horror Vivarium, starring Imogen Poots and Jesse Eisenberg as ac couple who gets trapped -- quite literally -- in a suburban housing complex. When the pair …