Return abspath to file with item content.

    Fetches the file from remote storage if required.

def fetch(dataset_uri, item_identifier):
    """Return abspath to file with item content.

    Fetches the file from remote storage if required.
    """
    dataset = dtoolcore.DataSet.from_uri(dataset_uri)
    click.secho(dataset.item_content_abspath(item_identifier))