parsers: replace generate_empty_element with derive

parsers/src/attention.rs

@@ -3,15 +3,15 @@
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
+use xso::{FromXml, IntoXml};
 
 use crate::message::MessagePayload;
+use crate::ns;
 
-generate_empty_element!(
-    /// Requests the attention of the recipient.
-    Attention,
-    "attention",
-    ATTENTION
-);
+/// Requests the attention of the recipient.
+#[derive(FromXml, IntoXml, Debug, Clone, PartialEq)]
+#[xml(namespace = ns::ATTENTION, name = "attention")]
+pub struct Attention;
 
 impl MessagePayload for Attention {}