Support add 'delete_on_termination' field to the voume attach API to
support configuring whether to delete the data volume when the server
is destroyed.
* Updating the ``nova volume-attachments`` command to show the
``delete_on_termination`` value if 2.79 or greater is used.
* The '--delete-on-termination' option is added to the `nova volume-attach`
CLI.
Depends-On: https://review.opendev.org/#/c/673133/
Part of blueprint support-delete-on-termination-in-server-attach-volume
Change-Id: I8dcf2fd21a2fd99ca4e05bd953fbbe026be3a619
cd396b8b61