message: Add a test for conversion between types using the right encoding
diff: @@ -33,7 +33,6 @@ use secp256k1::util::{
  COMPRESSED_PUBLIC_KEY_SIZE, FULL_PUBLIC_KEY_SIZE, SECRET_KEY_SIZE, SIGNATURE_SIZE,
  };
  use secp256k1::{recover, sign, verify, Message, RecoveryId};
  -use zeroize::Zeroize;
  use zx_bip44::BIP44Path;
  use crate::signature::{Signature, SignatureBLS, SignatureSECP256K1};
  @@ -59,8 +58,6 @@ impl AsRef<[u8]> for CborBuffer {
  pub const SIGNATURE_RECOVERY_SIZE: usize = SIGNATURE_SIZE + 1;
  /// Private key buffer
  -#[derive(Zeroize, Debug)]
  -#[zeroize(drop)]
  pub struct PrivateKey(pub [u8; SECRET_KEY_SIZE]);
  /// Public key buffer
  