db: Add host_ip and supported_instances to compute_nodes

In order to remove compute capabilities being broadcast via RPC to the
schedulers, host_ip and supported_instances, the two pieces of data the
scheduler uses that aren't in the database today, need to be added.
In the scope of this blueprint, only the way the filters are getting
their data is changed, not how the data is generated or anything else.

host_ip is used by the affinity_filter and supported_instances is used
by image_props_filter.

Part of bp no-compute-fanout-to-scheduler

Change-Id: I72371260159c9fdffcdb57209095fc103b6dd79e
Merge "db: Add host_ip and supported_instances to compute_nodes"