Function register_catalog_object 

fn register_catalog_object(
    catalog: &mut TestCatalog,
    name_to_id: &mut BTreeMap<String, GlobalId>,
    id: GlobalId,
    sql_typ: SqlRelationType,
) -> Result<()>

Register a referenceable object in the parser catalog under its global-id name (e.g. u1000), recording the name-to-id mapping so the parsed Gets — which carry the catalog’s own assigned ids — can be remapped back to the script’s ids.