always create subclass type from cs_rawObject

Sources/NSEntityDescription+DynamicModel.swift

@@ -31,6 +31,17 @@ import Foundation
 
 internal extension NSEntityDescription {
     
+    @nonobjc
+    internal var dynamicObjectType: DynamicObject.Type? {
+        
+        guard let userInfo = self.userInfo,
+            let typeName = userInfo[UserInfoKey.CoreStoreManagedObjectTypeName] as! String? else {
+                
+                return nil
+        }
+        return (NSClassFromString(typeName) as! DynamicObject.Type)
+    }
+    
     @nonobjc
     internal var coreStoreEntity: DynamicEntity? {