Return file info in `GetPrivateUrlDataset` use case

[vera]

The dataverse API for retrieving a dataset using a private URL /api/datasets/privateUrlDatasetVersion/... returns information about dataset files, but the transformer used by the GetPrivateUrlDataset use case doesn't transform it, so it's not returned:

dataverse-client-javascript/src/datasets/infra/repositories/DatasetsRepository.ts

Lines 56 to 68 in 0043ddd

	public async getPrivateUrlDataset(token: string, keepRawFields: boolean): Promise<Dataset> {
	return this.doGet(
	this.buildApiEndpoint(this.datasetsResourceName, `privateUrlDatasetVersion/${token}`),
	false,
	{
	returnOwners: true
	}
	)
	.then((response) => transformVersionResponseToDataset(response, keepRawFields))
	.catch((error) => {
	throw error
	})
	}

It would be useful to receive the file info from that use case.

Should the use case/transformer be extended? If yes, I'd be open to creating a PR for that.