This patch adds the '--cluster' optional argument to the 'volume
migration' command. This allows users to migrate volumes to a
destination cluster instead of a specific host, which is particularly
useful in Active-Active configurations.
The '--cluster' option requires Cinder API microversion 3.16 or
higher. The '--host' and '--cluster' options are mutually exclusive;
one of them must be provided for the migration to start.
Change-Id: Ibd45ac35e39a2a9f88a39f8041c06c4469727098
Signed-off-by: hongp <inyong.hong@samsung.com>
78e0bf023b