Network Validation in Command Line Inputs

[tareknaser]

Description

Currently, coffee does not validate if the network supplied in the command line is valid.
Running coffee -n remote list by mistake creates /Users/tareknasser/.coffee/remote

[vincenzopalazzo]

I did too :) we should validate the network is one of the cln supported one

Shoulds be really trivial

[vincenzopalazzo]

@Anyitechs there is no need to ask or advertize that you are working on some issue, just open a PR

[vincenzopalazzo]

Marking the commit as out of scope, please @Anyitechs do not use the github issue as a direct chat with the maintainer, if maintainer want to be reached they have an email in the github profile.