How to get the original dataset name with username?

### Feature request

The issue is related to ray data https://github.com/ray-project/ray/issues/49008 which it requires to check if the dataset is the original one just after `load_dataset` and parquet files are already available on hf hub.

The solution used now is to get the dataset name, config and split, then `load_dataset` again and check the fingerprint. But it's unable to get the correct dataset name if it contains username. So how to get the dataset name with username prefix, or is there another way to query if a dataset is the original one with parquet available?

@lhoestq

### Motivation

https://github.com/ray-project/ray/issues/49008

### Your contribution

Would like to fix that.