[baremetal] Rename all to drop baremetal prefix

A few things differ between baremetal and virtual nodes:
- provisioning method;
- network setup;

Since now we support completely dynamic network config based on PDF +
IDF, as well as dynamic provisioning of VMs on jumpserver (as virtual
cluster nodes), respectively MaaS-driven baremetal provisioning, let's
drop the 'baremetal-' prefix from cluster model names and prepare for
unified scenarios.

Note that some limitations still apply, e.g. virtual nodes are spawned
only on jumpserver (localhost) for now.

JIRA: FUEL-310

Change-Id: If20077ac37c6f15961468abc58db7e16f2c29260
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>