in first-rows: change "columns" for "features"
In order to rely on the https://github.com/huggingface/datasets library instead of maintaining a layer in datasets-server, we will directly return the features.

This way, the vocabulary / types will be maintained in `datasets` and we will have a better consistency.

Also note that type inference, which wasn't implemented in `datasets`, is now available (for streaming, which is ok here): https://github.com/huggingface/datasets/blob/f5826eff9b06ab10dba1adfa52543341ef1e6009/src/datasets/iterable_dataset.py#L1255.

This means that we will have to adapt the client (https://github.com/huggingface/moon-landing/blob/main/server/lib/DatasetApiClient.ts and https://github.com/huggingface/moon-landing/blob/main/server/lib/DatasetViewer.ts) as well.
in first-rows: change "columns" for "features": In order to rely on the https://github.com/huggingface/datasets library instead of maintaining a layer in datasets-server, we will directly return the features.

This way, the vocabulary / types will be maintained in `datasets` and we will have a better consistency.

Also note that type inference, which wasn't implemented in `datasets`, is now available (for streaming, which is ok here): https://github.com/huggingface/datasets/blob/f5826eff9b06ab10dba1adfa52543341ef1e6009/src/datasets/iterable_dataset.py#L1255.

This means that we will have to adapt the client (https://github.com/huggingface/moon-landing/blob/main/server/lib/DatasetApiClient.ts and https://github.com/huggingface/moon-landing/blob/main/server/lib/DatasetViewer.ts) as well.