multiple fullstack nits/cleanups before release (#4852)

* feat: `:arg` syntax for serverfn

* add better decode/encode verify message

* allow catch-all query args

* add rebind

* implement websocket frames for `Streaming`

* fix lazy init

* wip... serverfnstate

* wip...

* wip: serverfns require Send/Sync, let's fix that

* wip...

* small cleanup

* fix hang by actually spawning the tokio task

* clippy

* fix parameter catchall binding

* fix lychee

* doc tests

examples/07-fullstack/fullstack_hello_world.rs

@@ -18,7 +18,7 @@ fn main() {
     });
 }
 
-#[get("/api/{name}/?age")]
+#[get("/api/:name/?age")]
 async fn get_message(name: String, age: i32) -> Result<String> {
     Ok(format!("Hello {}, you are {} years old!", name, age))
 }