message: Add _bytes user literal for creating bytes from hex
diff: @@ -27,4 +27,13 @@ inline std::string hex(bytes_view data)
  {
  return hex(data.data(), data.size());
  }
  +
  +inline namespace literals
  +{
  +/// Operator for "" literals, e.g. "0a0b0c0d"_bytes.
  +inline fizzy::bytes operator""_bytes(const char* literal, size_t /*length*/)
  +{
  + return fizzy::from_hex(literal);
  +}
  +} // namespace literals
  } // namespace fizzy
  