Revert "fix: remove "type" and "types" value declarations from OBJECT enum"

This reverts commit 7c0a6af.

Author: K5qu4r3d

modules/swagger-core/src/main/java/io/swagger/v3/core/util/PrimitiveType.java

@@ -239,7 +239,7 @@ public Schema createProperty() {
         }
         @Override
         public Schema createProperty31() {
-            return new JsonSchema();
+            return new JsonSchema().typesItem("object").type("object");
         }
     };