Add ability to specify announced address(es)

[vpavlin]

Is your feature request related to a problem? Please describe.
In nwaku we have these config options:

 --ext-multiaddr           External multiaddresses to advertise to the network. Argument may be repeated..
 --ext-multiaddr-only      Only announce external multiaddresses [=false].

It is especially useful if you run Kubernetes environment, but might also be useful when using any kind of port-forwarding where extrnal port may not match the listen port

Describe the solution you'd like

Allow specifying listenAddress and externalAddress separately - it is then up to the operator to make sure the connections coming to externalAddress are actually tunneled to listenAddress

Describe alternatives you've considered

We have not found any other working solution in nwaku for this particular issue

Additional context

Original issue from nwaku: waku-org/nwaku#1797