integration: Test vHost User numa awareness

integration: Test vHost User numa awareness

Open vSwitch with DPDK can optimize memory usage
in case of NUMA architecture to avoid unnecessary
memory access across NUMA slots. In a nutshell,
PMD threads serving virtual NICs are co-located at
the same NUMA slot as QEMU instance, which is using
these NICs.
This patch adds new (functional) integration testcase,
which verifies OVS vHost User numa awareness feature.
Step driven test objects were updated to allow a call
of OS utilies and evaluation of conditions. Also the
documentation was updated with the list of supported
test objects and their methods.

JIRA: VSPERF-377

Change-Id: I184e71e066d27b5b9fc9e6a9f7e240e2d1b5a0fa
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Ciara Loftus <ciara.loftus@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Christian Trautman <ctrautma@redhat.com>
Reviewed-by: Bill Michalowski <bmichalo@redhat.com>
Reviewed-by: Antonio Fischetti <antonio.fischetti@intel.com>