Make ws::Message an enum for easier frame type matching (#116)

* feat(ws): make Message an enum to allow pattern matching

* fix(examples): update to new websockets `Message`

* fix(ws): remove wildcard imports

* fix(examples/chat): apply clippy's never_loop

* style: `cargo fmt`

* docs:add license notes above parts that are copied

* fix(ws): make CloseCode an alias to u16

* fix: move Message from src/ws/mod.rs to src/extract/ws.rs

* docs: add changelog entry about websocket messages

* fix: remove useless convertions to the same type

examples/websocket.rs

@@ -84,7 +84,11 @@ async fn handle_socket(mut socket: WebSocket) {
     }
 
     loop {
-        if socket.send(Message::text("Hi!")).await.is_err() {
+        if socket
+            .send(Message::Text(String::from("Hi!")))
+            .await
+            .is_err()
+        {
             println!("client disconnected");
             return;
         }