vCenter integration UI added

Added vcenter input info for vcenter into settings and changed wizard and dependencies.
Generate Cirros metadata in Nailgun.
Customize labels for Cluster settings groups.

Must be merged simultaneously with https://review.openstack.org/#/c/87397

Implements: blueprint fuel-vmware-hypervisor

Change-Id: Ie46be6dc4a1219f8fbbf88ef6f6691e8476bf4d6
Merge "vCenter integration UI added"