Make visor listen for stcp transports automatically

[jdknives]

Feature description

Get local IP address and make visor listen for stcp transports on that address and port 7777 by default.

Is your feature request related to a problem? Please describe.
Currently, we have to manipulate the configuration file manually to setup stcp transports and set the local IP and port to listen on. All of that should be automated.

[pikomonde]

Hmm.. So, previously to make the visor run, we should manipulate manually the config file, which one? This one /skywire-config.json?

Then the changes should make the app to listen to stcp on what address? Is it address from the PK on /skywire-config.json? So I assume the default local IP is 127.0.0.1:7000.

So, in config, when the stcp.local_address is not there, by default the app will set it to 127.0.0.1:7000?