Function process_error 

pub async fn process_error<S, ST>(
    socket: &mut Framed<S, PgWireMessageServerCodec<ST>>,
    error: PgWireError,
    wait_for_sync: bool,
) -> Result<(), Error>
where
    S: AsyncRead + AsyncWrite + Unpin + Send + Sync + 'static,

Send an error response to the client and update connection state accordingly.