message: add way to access and build the bft object
diff: @@ -100,6 +100,17 @@ impl property::Deserialize for LeaderId {
  }
  }
  +impl AsRef<[u8]> for LeaderId {
  + fn as_ref(&self) -> &[u8] {
  + self.0.as_ref()
  + }
  +}
  +impl From<PublicKey<SIGNING_ALGORITHM>> for LeaderId {
  + fn from(v: PublicKey<SIGNING_ALGORITHM>) -> Self {
  + LeaderId(v)
  + }
  +}
  +
  #[cfg(test)]
  pub mod test {
  use super::*;
  