support all options of kubectl port-forward

[kamilsk]

• [x] kubectl port-forward mypod 5000 6000 Listen on ports 5000 and 6000 locally, forwarding data to/from ports 5000 and 6000 in the pod
• [x] kubectl port-forward mypod 8888:5000 Listen on port 8888 locally, forwarding to 5000 in the pod
• [ ] kubectl port-forward mypod :5000 Listen on a random port locally, forwarding to 5000 in the pod

[kamilsk]

do I need to generate some port or use default os behavior? how I can receive port number in last case?