Work around Lmod bug in KDE update packages, with new mechanism
    
    It seems like the situation where we need to pull an update from
    updates-testing into all update tests to work around some known
    issue is going to keep happening. So instead of constantly
    adding and then entirely removing bespoke lines for each specific
    workaround, let's have a permanent mechanism for doing this: a
    hash with release numbers as keys, and arrayrefs of update IDs
    as values, and a block to call `bodhi updates download` on the
    appropriate array for the release under test. This way, to add
    or remove a workaround you just update the hash. If we're at a
    point where *no* workarounds are needed the %workarounds hash
    can be made entirely empty (it must exist, though) and the code
    will be a clean no-op.
    
    The actual workaround here pulls in Lmod updates I just sent out
    to work around this issue in one of the KDE update tests:
    
    https://openqa.fedoraproject.org/tests/497160#step/base_update_cli/11
    
    there's some code in Lmod that gets sourced in bash profiles
    which breaks openQA's `validate_script_output` by blurping two
    lines of informational output into the output of the script.
    The update backports a change from upstream Lmod master that
    sends that informational output to stderr instead of stdout.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>