Get our project VCF, either from the population or the variant batch file.

def _get_project_vcf(x, suffix=""):
    """Get our project VCF, either from the population or the variant batch file.
    """
    vcfs = _get_variant_file(x, ("population", "vcf"), suffix=suffix)
    if not vcfs:
        vcfs = _get_variant_file(x, ("vrn_file_batch", ), suffix=suffix, ignore_do_upload=True)
        if not vcfs and x.get("variantcaller") == "ensemble":
            vcfs = _get_variant_file(x, ("vrn_file", ), suffix=suffix)
    return vcfs