Fix mac address and task_state in baremetal-node-list

Currently nova baremetal-node-list doesn't display the
list of MAC addresses for each node because this is part
of the interfaces object, and not a top level field.

It also doesn't display the task state, which is very useful
when trying to find which nodes have failed to build.

This change fixes both issues

Change-Id: If7a3bcab1220be400519ac811bd727ca8ff85827
Closes-Bug: #1308147
Merge "Fix mac address and task_state in baremetal-node-list"