This makes the resource tracker look up and create ComputeNode objects
by uuid instead of nodename. For drivers like ironic that already
provide 'uuid' in the resources dict, we can use that. For those
that do not, we force the uuid to be the locally-persisted node
uuid, and use that to find/create the ComputeNode object.
A (happy) side-effect of this is that if we find a deleted compute
node object that matches that of our hypervisor, we undelete it
instead of re-creating one with a new uuid, which may clash with our
old one. This means we remove some of the special-casing of ironic
rebalance, although the tests for that still largely stay the same.
Change-Id: I6a582a38c302fd1554a49abc38cfeda7c324d911
23c5f3d585