TEX11 — DDS Mapping for schema of extended data is unclear

The DDS IDL for the schema of extended data is
"ExtendedData__id_type _id;"
This is missing the name, missing description and is an inappropriate underlying type - int. It would be natural to refer to a schema through a schema prefix.

Schema to be reference object itself that can be included by-value

Change the association to the ExtensionSchema class in the PIM to be a composition.
Also make it mandatory (note that the name of the Schema could be empty if used without a formal schema).
Also schema should be the name of the target role not of the relation.