feat: record the namespace a view's unqualified names resolve against

A view outlives the session that declared it, so the namespace path its
query resolved against travels with it, beside the database. Without it
a reader would resolve an unqualified name against its own default and
read a different table.

`ViewDescription` carries `default_namespace_path`; it crosses the wire
as `default_namespace`, a path like `namespace`, absent for the root.

python/src/connection.rs

@@ -106,7 +106,7 @@ fn parse_default_namespace_path(path: Option<Bound<'_, PyAny>>) -> PyResult<Vec<
 
 /// A view description on its way to Python: name, namespace, query, default
 /// database, and the schema as pyarrow renders it.
-type PyViewDescription = (String, Vec<String>, String, String, Py<PyAny>);
+type PyViewDescription = (String, Vec<String>, String, String, Vec<String>, Py<PyAny>);
 
 /// A view description as a plain tuple, with the schema converted to the
 /// pyarrow schema the caller would get from any other lancedb API. The Python
@@ -120,6 +120,7 @@ fn view_description_to_py(view: lancedb::view::ViewDescription) -> PyResult<PyVi
             view.namespace_path,
             view.query,
             view.default_database,
+            view.default_namespace_path,
             schema,
         ))
     })