Comment 7 for bug 1760303

Reviewed: https://review.openstack.org/592086
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=77a831de8b5ef573527b844c852bf22f775d7787
Submitter: Zuul
Branch: stable/queens

commit 77a831de8b5ef573527b844c852bf22f775d7787
Author: Matt Riedemann <email address hidden>
Date: Sat Mar 31 10:28:29 2018 -0400

    Fix cancel_all_events event name parsing

    The cancel_all_events function was incorrectly assuming
    that event tags didn't have dashes in them, but they all
    do since they are either port or volume IDs, which are UUIDs.

    Instead of just storing our event data indexed by the composite
    event key, we should just store the name and tag distinctly so
    that there is no question about how to dissect the two from the
    key later. This is all internal record-keeping inside of the
    compute manager, so we can change it to whatever we want.

    This includes a slight change to the internal virtapi interface
    for wait_for_instance_event(), which removes the ability to
    pass composite event keys as strings instead of (name, tag)
    tuples. In reality, none of the virt code was using the key string
    format, so this just cleans up a few tests that were. It makes
    that interface less ambiguous, which is good anyway.

    Change-Id: I15f041e820c2dabe82e8e25bf77f9cc86330a76a
    Closes-Bug: #1760303
    (cherry picked from commit d9369d034cb0694def2510885ddfb9b039cbad49)