arti-relay: improve cli and add config loading
This refactors some of the cli logging, adds config loading, and adds a placeholder logger. This is a first iteration, and we can add/change/refactor functionality as we need to.
This also removes the ArtiRelayBuilder
since it's a bunch of boilerplate code at the moment, and I'm not sure that we'll actually need it in the future. Since we'll be the only users of ArtiRelay
, I think we'll only need one way of building an ArtiRelay
, and we don't have enough arguments to justify a builder.
Part of #1736.
Edited by opara