Add missing baremetal API tests

This adds some missing API test coverage for listing ports by
node id, node by instance uuid, node by chassis id, and listing
nodes by instance association status.  In addition to the required
client changes, this adds a common waiter for baremetal nodes which
can be leveraged in the future by the baremetal scenario tests.

Change-Id: I175da30516d697a2b3115353f405e0fe3e1ccc76
Merge "Add missing baremetal API tests"