samples: Add generic L3 forwarder tests

samples: Add generic L3 forwarder tests

A generic throughput test case that can be used as a
stub code for a Linux-based VNF configured as an L3 forwarder.

Supported context:
* Standalone OVSDPDK and SRIOV
* Baremetal

Code changes:
* Allow pmd-cpu-mask and lcore mask for OVS DPDK
* router_vnf.py - configures interface IP addresses and static arp entries
  using ip command
* NFVi KPIs
* Allow cputune tag for standalone context to be able to PIN on NUMA 1 cpus

SRIOV Test cases:
* RFC2544 Ethernet framesizes, 128K Flows
* 2,4 and 6 ports
* 2 and 3 vcpus per port
*
OVSDPDK Test cases:
* RFC2544 Ethernet framesizes, 128K Flows
* 2 and 4 ports
* 2 vcpus per port
* 2 PMD threads per port

TODO:
* Documentation
* Add 6 ports tests

References:
* router_vnf.py is based on sample_vnf.py
* tc_*.yaml files are based on acl/vfw test case files

Added unitests
Added get_stats to parse ip -s link

Change-Id: Id1b969d5420dfcab7c1e695acbd2cd1655747efe
Signed-off-by: Dino Simeon Madarang <dinox.madarang@intel.com>
Signed-off-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Reviewed-by: Alain Jebara <alain.jebara@intel.com>
Reviewed-by: Deepak S <deepak.s@linux.intel.com>
Reviewed-by: Emma Foley <emma.l.foley@intel.com>
Reviewed-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>
Reviewed-by: Ross Brattain <ross.b.brattain@intel.com>
Reviewed-by: Edward MacGillivray <edward.s.macgillivray@intel.com>
Signed-off-by: Dhaval Patel <dhaval.r.patel@intel.com>
Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>