Add UnknownMessage struct

src/network.rs

@@ -211,6 +211,22 @@ impl NewTxMessage {
     }
 }
 
+#[derive(Debug, Serialize, Deserialize, Tsify)]
+#[tsify(into_wasm_abi, from_wasm_abi)]
+pub struct UnknownMessage {
+    pub sender: String,
+    pub message: String,
+}
+
+impl UnknownMessage {
+    pub fn new(sender: String, message: String) -> Self {
+        Self {
+            sender,
+            message,
+        }
+    }
+}
+
 #[derive(Debug, Serialize, Deserialize, Tsify)]
 #[tsify(into_wasm_abi, from_wasm_abi)]
 pub struct AnkNetworkMsg {