Complete raise if dataset requires manual download
Follow-up of:
- #1309

See: https://github.com/huggingface/datasets-server/issues/1307#issuecomment-1579288660

Fix partially #1307.

EDIT:
TODO as requested by @severo:
- [x] Raise `DatasetManualDownloadError` from `config-split-names-from-streaming`
- [ ] ~~Propagate the error codes to the aggregator steps (config -> dataset, in this case) so that we can show the appropriate message on the Hub~~
  - To be done in another PR
Complete raise if dataset requires manual download: Follow-up of:
- #1309

See: https://github.com/huggingface/datasets-server/issues/1307#issuecomment-1579288660

Fix partially #1307.

EDIT:
TODO as requested by @severo:
- [x] Raise `DatasetManualDownloadError` from `config-split-names-from-streaming`
- [ ] ~~Propagate the error codes to the aggregator steps (config -> dataset, in this case) so that we can show the appropriate message on the Hub~~
  - To be done in another PR