message: Implememt sorting for TxIDs
diff: @@ -24,7 +24,7 @@ const OVERWINTER_TX_VERSION: u32 = 3;
  const SAPLING_VERSION_GROUP_ID: u32 = 0x892F2085;
  const SAPLING_TX_VERSION: u32 = 4;
  -#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
  +#[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq, Hash)]
  pub struct TxId(pub [u8; 32]);
  impl fmt::Display for TxId {
  