Allow initializing NamedListPanel title dict as parameter

panel/layout/base.py

@@ -564,8 +564,9 @@ def __init__(self, *items: list[Any | tuple[str, Any]], **params: Any):
                     'as positional arguments or as a keyword, not both.'
                 )
             items = params.pop('objects')
-        params['objects'], self._names = self._to_objects_and_names(items)
+        params['objects'], names = self._to_objects_and_names(items)
         super().__init__(**params)
+        self._names = names
         self._panels = defaultdict(dict)
         self.param.watch(self._update_names, 'objects')
         # ALERT: Ensure that name update happens first, should be