erp5_catalog: Add CatalogFilter property_sheet to PythonScript class

Use filter attributes as property. Same as done for ERP5 SQL Methods.
This way maintains consistency between sub-objects of Catalog, i.e,
SQL Method and Python Script.

product/ERP5/Document/PythonScript.py

@@ -87,6 +87,7 @@ class PythonScript(XMLObject, ZopePythonScript):
                       , PropertySheet.CategoryCore
                       , PropertySheet.DublinCore
                       , PropertySheet.PythonScript
+                      , PropertySheet.CatalogFilter
                       )
 
     def __init__(self, *args, **kw):