[RFE] Test secondary interface

[jtaleric]

Is your feature request related to a problem? Please describe.
Nope

Describe the solution you'd like
Allow for a secondary interface to be used for throughput testing

[jtaleric]

To do this
1 ) Update the confg yaml to include a multus option. Like

---
tests:
  - TCPStream:
    parallelism: 1
    profile: "TCP_STREAM"
    duration: 10
    samples: 3
    messagesize: 1024
    multus: <net-attach-name>

2 ) update the client/server podSpec to include the cncf.io/networks annotation for the user-defined net-attach interface

3 ) capture the ip address of the multus interface.

[jtaleric]

https://github.com/k8snetworkplumbingwg/multus-cni/blob/master/docs/quickstart.md#network-status-annotations