For those who are looking for unziping features, Embedded Python (for IRIS 2021.2+) allows you to use zipfile Python lib. For instance:

ClassMethod UnZip(pZipFileName As %String, pExtractToDir As %String) [ Language = python ]
{
    #; solution based on this one: https://stackoverflow.com/a/3451150/345422
    import zipfile
    with zipfile.ZipFile(pZipFileName, 'r') as zip_ref:
        zip_ref.extractall(pExtractToDir)
}

Or

ClassMethod UnZip2(pZipFileName As %String, pExtractToDir As %String)
{
    Set zipfile = $SYSTEM.Python.Import("zipfile")
    Do zipfile.ZipFile(pZipFileName, "r").extractall(pExtractToDir)
}

Tested on iris-ml-community:2021.2.0.617.0-zpm