do not depend on core lightning dependencies when not running the cln runner

[vincenzopalazzo]

Iterating on an ldk https://github.com/lightningdevkit runner where @Psycho-Pirate worked on that it is a fork of this repository.

Oh man installing pyln-client is a pain if you fall in an architecture where there are no binary exported, before you need postgress, then you need to compiler grpcio if you can find out what it is missing or you give up before.

So a library that provides a simple unix socket wrapper should not be so painful to install.