[cinder] volume list query ("managing" statuses) spec
The spec is https://review.opendev.org/#/c/726070/
I took the action item at today's virtual mid-cycle meeting to summarize
the discussion on the review so that the spec can be revised. While
doing that, I looked through the code carefully, and I think that the
spec is actually on the right track, though there seem to be several
bugs associated with this issue.
In any case, I just left an enormous comment on the review. I need
other reviewers to read through and comment/respond so that haixin and
zhangbailin can get some consensus on how to revise the spec.