Adds dynamic host volumes to argument autocomplete for the `volume status` and
`volume delete` commands. Adds flag autocompletion for those commands plus
`volume create`.
Ref: https://github.com/hashicorp/nomad/pull/24479
The command line flag parsing and the HTTP header parsing for CSI secrets
incorrectly split at more than one '=' rune, making it impossible to use secrets
that included that rune.
Add new commands for creating, deleting, and listing external storage
volumes. Includes HCL decoding update for volume spec so that we can humanize
capacity bytes input values.
