Allow tagging leases

[larsks]

We should permit non-admin users to apply tags to leases, in much the same way as most of the networking subcommand allow tagging:

$ openstack help network create
...
  --tag <tag>   Tag to be added to the network (repeat option to set multiple tags)
...

As we move forward in the innabox project with both cluster fulfillment and baremetal fulfillment, I think it will become necessary to differentiate between "leases acquired for the purposes of cluster deployment" and "leases acquired for bare metal deployment". For example, in order to support idempotency, if we successfully acquire leases but then fail in a subsequent step, we want to be able to re-discover those leases and understand their intended purpose.

The esi lease list command show support a --tag option that would restrict the list to the specified tag. For reference, the networking commands implement these options to the list command:

  --tags <tag>[,<tag>,...]
                        List networks which have all given tag(s) (Comma-separated list of tags)
  --any-tags <tag>[,<tag>,...]
                        List networks which have any given tag(s) (Comma-separated list of tags)
  --not-tags <tag>[,<tag>,...]
                        Exclude networks which have all given tag(s) (Comma-separated list of tags)
  --not-any-tags <tag>[,<tag>,...]
                        Exclude networks which have any given tag(s) (Comma-separated list of tags)