Refactor VHOST code

Refactor VHOST code

CSIT-1164 Create VM vhost tests for 2-node topology
CSIT-1173 Implement VM vhost KWs for 2-node topology

- Cleanup QemuUtils.py Library (PEP8, some TODOs, readability, multi queue,
ring size, qemu version detection)
- Cleanup VHOST KWs perf (Unify running QEMU on N-node topology)
- Add ability to configure Queues, Hyperthreading, automatically compute
number of CPU for VM/Testpmd and RXQ for Testpmd workload.
- Partial cleanup of configuration KWs (l2xc, l2bd) for 2-node
- Create IPv4 2-node KW

Change-Id: I8aae1355bafa651de715cd438fe706c443ea1d88
Signed-off-by: Peter Mikus <pmikus@cisco.com>