ei: add support for libei

src/tasks/slow_clients.rs

@@ -12,3 +12,16 @@ impl SlowClientHandler {
         }
     }
 }
+
+pub struct SlowEiClientHandler {
+    pub state: Rc<State>,
+}
+
+impl SlowEiClientHandler {
+    pub async fn handle_events(&mut self) {
+        loop {
+            let client = self.state.slow_ei_clients.pop().await;
+            client.check_queue_size().await;
+        }
+    }
+}