client: implements event/updates websocket

kordophone/src/model/update.rs

@@ -0,0 +1,21 @@
+use serde::Deserialize;
+use super::conversation::Conversation;
+use super::message::Message;
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct UpdateItem {
+    #[serde(rename = "messageSequenceNumber")]
+    pub seq: u64,
+
+    #[serde(rename = "conversation")]
+    pub conversation: Option<Conversation>,
+
+    #[serde(rename = "message")]
+    pub message: Option<Message>,
+}
+
+impl Default for UpdateItem {
+    fn default() -> Self {
+        Self { seq: 0, conversation: None, message: None }
+    }
+}