HCK-7143: allow entities to be selected as external reference (#40)

Author: serhii-filonenko

types/object.json

@@ -25,8 +25,9 @@
 				"time",
 				"timetz",
 				"super",
-				"varbyte"
+				"varbyte",
+				"object"
 			]
 		}
 	}
-}
+}