//! Note this is not part of the specs, but follows lnd's signing and verifying protocol, which can is defined as follows:
//!
//! signature = zbase32(SigRec(sha256d(("Lightning Signed Message:" + msg)))
//! Note this is not part of the specs, but follows lnd's signing and verifying protocol, which can is defined as follows:
//!
//! signature = zbase32(SigRec(sha256d(("Lightning Signed Message:" + msg)))