Migrate 4G Network Topology example from nsm/examples

[denis-tingaikin]

We need to migrate https://github.com/networkservicemesh/examples/tree/master/examples/4g-network example from old styled NSM to the multirepo nsm. The example can be useful for the folks.

It seems to me all functional parts for this are done and we need to just re-create the example line by line in deployments-k8s repository.

See at source https://github.com/networkservicemesh/examples/tree/master/examples/4g-network