Max_vcpus_topology: ensure that the VM gets correct topology with maximum vcpus

[rh-jugraham]

Automates the case that verifies the vm can start with vcpus which is equal to host online cpu number and vm topology is consistent to those configured.

Depends on:

• vm_xml: set_vm_vcpus() support clusters avocado-framework/avocado-vt#4006

Scenarios + sub-scenarios considered:

• Only 1 socket
  • No clusters defined, so default is 1
  • clusters = 2n, like 2, 4, 6
• Only 1 core per socket
• More than one core per socket
  • More than one socket, clusters defaults to 1
  • clusters = 2n, like 2, 4, 6 ...

Evidence of tests passing: