Baremetal host power statuses are handled as strings in airshipctl.
Invoking remotedirect on a host that is powered off will result in a
remotedirect failure; therefore, the power status of a host needs to be
verified before remotedirect can begin. This change adds strict typing
to baremetal power statuses so airshipctl can verify the status of a
remote host before performing remotedirect regardless of the client type
(e.g. redfish, other).
Signed-off-by: Drew Walters <email@example.com>