message: feat(error): add `Error::message`
  This adds Error::message which returns the message that is unique to the error, without the message from the source. That way users can create a newtype around hyper::Error and use this in the Display impl to work around
  Closes
diff: @@ -396,6 +396,11 @@ impl Error {
  }
  }
  + /// The error's standalone message, without the message from the source.
  + pub fn message(&self) -> impl fmt::Display + '_ {
  + self.description()
  + }
  +
  fn description(&self) -> &str {
  match self.inner.kind {
  Kind::Parse(Parse::Method) => "invalid HTTP method parsed",
  