Consider deployment flavor consisting of a more complete switch plane

[Gerrit91]

For integration testing purposes it could be interesting to add another deployment flavor to the mini-lab where we also spin up VMs for spines, exits, mgmt-servers, etc.

This can probably not be called "mini" anymore, but there is a need for something like this. It is useful in order to integration test more sophisticated network scenarios, plus it accelerates moving partition deployment roles to metal-roles such that adopters can use them for bootstrapping their partitions.