Add "tier" field to blockdev list
Add "tier" field to blockdev list

We now support data and cache blockdevs, so list both with this command
but indicate which tier a blockdev belongs to.

Signed-off-by: Andy Grover <b7d524d2f5cc5aebadb6b92b08d3ab26911cde33@redhat.com>

stratis-storage/stratis-cli,stratis-storage/stratis-cli