Add extracted fastq files of HLA alleles for typing.

def _add_hla_files(data):
    """Add extracted fastq files of HLA alleles for typing.
    """
    if "hla" not in data:
        data["hla"] = {}
    align_file = dd.get_align_bam(data)
    hla_dir = os.path.join(os.path.dirname(align_file), "hla")
    if not os.path.exists(hla_dir):
        hla_files = None
    else:
        hla_files = sorted(list(glob.glob(os.path.join(hla_dir, "%s.*.fq" % os.path.basename(align_file)))))
    data["hla"]["fastq"] = hla_files
    return data