NSB Prox BM test case fixes for scale up

NSB Prox BM test case fixes for scale up

YARDSTICK-839

In a scale-up test the VNF number can start from
0 to MAX (num_vnf-1)

The NSB PROX BM test nodes are currently marked as:
    tg__0: trafficgen_1.yardstick
    vnf__0: vnf.yardstick
They need to be changed to the below:
    tg__0: tg_0.yardstick
    vnf__0: vnf_0.yardstick

Changes done are:
- All BM Prox test cases have tg_0 and vnf_0 as default
  test nodes
- The prox-baremetal-1/2/4.yaml sample pod file
- Cleaned Up some unused Prox test/config files

Change-Id: I819011bcb35eda62b17dd3e1035918918c582b13
Signed-off-by: Abhijit Sinha <abhijit.sinha@intel.com>