THE AMERICAN INSTITUTE OF ARCHITECTS has presented this year's Honor Awards, considered the most prestigious for architecture in the United States. Among the 20 winners are: Procter & Gamble Offices in Cincinnati, Sulzer Library in Chicago, Middleton Inn in Charleston, S.C., New York Public Library Restoration, Lewis Thomas Laboratory, Princeton, N.J., and Claudia's, a tiny cinnamon-roll shop, in San Diego. A 36-ACRE SCULPTURE PARK will be created to show off works by Henry Moore just south of the Nelson-Atkins Museum of Art in Kansas City, Mo. The park will be financed by the museum, the Hall Family Foundations, and the city's parks and recreation department. It will open in the fall of 1988, but five Moore sculptures will be previewed in various public sites this summer. GEORGI TOVSTONOGOV is making his American directorial debut at McCarter Theatre, Princeton, N.J., where Chekhov's ``Uncle Vanya'' is being performed through May 31. Mr. Tovstonogov is the artistic director of the Gorky Theatre in Leningrad. Nagle Jackson, McCarter's artistic director, has been invited to direct at Tovstonogov's theater next year. Eduard Kochergin, resident designer at the Gorky, came to the US to design the sets and costumes for the McCarter production.