Since the code for creating and using a macaroon service is the same for
multiple projects (pool, loop, litd etc), the code has been unified in
lndclient. So this commit removes the macaroon service code and instead
uses the lndclient code.
To itest our autolooper, we need to be able to trigger dispatch on
demand. This functionality is included in a separate rpc server behind
a dev flag. Since it is unlikely that we need to split loop into
multiple rpc servers, this commit simply adds an additional debug server
rather than opting for a full subserver setup.
