TERRACE LOVERS REJOICE. Sun-flooded home in full-service Sutton Place co-op has that rarest of features - a huge private terrace with open south, east and north city views. Large enough for two seating areas and grand entertaining, it simultaneously offers a private and peaceful refuge from the stresses of city life.    Inside, the layout of this renovated one bedroom with two distinct living spaces is anything but typical. The loft-like living room has dual exposures from which you can enjoy both sunsets and terrace greenery. Step into the outrageously sunny den with its skylights, walls of windows and open city views. Sit down at the breakfast bar in the open kitchen outfitted with Viking, Subzero and Miele appliances and Poggenpohl cabinetry, or use the den as a more formal dining room. The comfortable east-facing bedroom offers a very large closet and a second entry to the terrace. In addition to a windowed full bath, there is a powder room for guests.    357 East 57th Street is a full-service cooperative, with a 24-hour doorman, live-in superintendent, furnished roof deck, central laundry facilities, and direct access to an on-site parking garage. Close to multiple subway lines and bus routes, fine dining and shopping (including Whole Foods market), and Sutton Place Park, the location could not be better. Pet friendly too!