WritersState on ArcSwao + Preferred Endpoint on ArcSwap + Two-map Rotation for Desync Dedup

Co-Authored-By: brekotis <93345790+brekotis@users.noreply.github.com>

src/transport/middle_proxy/pool_config.rs

@@ -112,7 +112,7 @@ impl MePool {
 
     pub async fn reconnect_all(self: &Arc<Self>) {
         let ws = self.writers.read().await.clone();
-        for w in ws {
+        for w in ws.iter() {
             if let Ok(()) = self
                 .connect_one_for_dc(w.addr, w.writer_dc, self.rng.as_ref())
                 .await