Bump warp and begin axum migration (#9001)

- Bump `warp` to 0.4. This unifies `warp` and `axum` onto the same `http`, `hyper`, `h2`, `rustls`, etc versions.
- Create `axum_utils` which contain common functions and types
- Begins migration of all HTTP API servers from warp to axum


Co-Authored-By: Mac L <mjladson@pm.me>

beacon_node/src/lib.rs

@@ -139,6 +139,7 @@ impl<E: EthSpec> ProductionBeaconNode<E> {
             .notifier()?
             .http_metrics_config(client_config.http_metrics.clone())
             .build()
+            .await
             .map(Self)
     }