Use default value for initialization

The default value returns a valid value for the initialization according
to the type hints. This lowers the type hints errors using mypy from 838
to 354.

Author: agners

src/controller/python/templates/python-cluster-Objects-py.zapt

@@ -76,9 +76,9 @@ class {{asUpperCamelCase name}}(Cluster):
 
 {{#zcl_attributes_server}}
 {{#if entryType}}
-    {{ asLowerCamelCase label }}: '{{zapTypeToPythonClusterObjectType entryType ns=(asUpperCamelCase parent.name)}}' = None
+    {{ asLowerCamelCase label }}: '{{zapTypeToPythonClusterObjectType entryType ns=(asUpperCamelCase parent.name)}}' = {{getPythonFieldDefault entryType ns=(asUpperCamelCase parent.name)}}
 {{else}}
-    {{ asLowerCamelCase label }}: '{{zapTypeToPythonClusterObjectType type ns=(asUpperCamelCase parent.name)}}' = None
+    {{ asLowerCamelCase label }}: '{{zapTypeToPythonClusterObjectType type ns=(asUpperCamelCase parent.name)}}' = {{getPythonFieldDefault type ns=(asUpperCamelCase parent.name)}}
 {{/if}}
 {{/zcl_attributes_server}}