Nova Instance Guest Metadata

There is currently a specless blueprint up in Nova for the other side of this: https://blueprints.launchpad.net/nova/+spec/ironic-guest-metadata

Right now, calls to Ironic from Nova are done without project credentials. This prevents us from using any information from the calling token to know what project should be used for setting node.lessee when [conductor]automatic_lessee=True. In order to enable this functionality, as well as provide basic instance metadata for operator troubleshooting cases, we will put selected portions of the nova instance metadata into node.instance_info at deploy, alongside the other metadata required to deploy.

This information will include:
- Information about the user/project who requested the instance
- Flavor name
- Any other useful metadata

This information will explicitly EXCLUDE:
- Information available elsewhere in Ironic
- Network-related metadata which may not be reliable in Ironic use cases

Once we have information on the user/project who requested the instance, we will then edit conductor code to implement setting node.lessee based on that metadata when automatic_lessee is enabled.