Remove the "expected" next ID

It's an unnecessary extra layer better handled locally.

coordinator/src/main.rs

@@ -870,6 +870,7 @@ pub async fn handle_processors<D: Db, Pro: Processors, P: P2p>(
     // Alternatively, a peek method with local delineation of handled messages would work.
 
     let msg = processors.recv().await;
+    // TODO: Check this ID is sane (last handled ID or expected next ID)
     if last_msg == Some(msg.id) {
       sleep(Duration::from_secs(1)).await;
       continue;

coordinator/src/processors.rs

@@ -28,8 +28,7 @@ impl Processors for Arc<MessageQueue> {
     self.queue(metadata, msg.into_bytes()).await;
   }
   async fn recv(&mut self) -> Message {
-    // TODO: Use a proper expected next ID
-    let msg = self.next(0).await;
+    let msg = self.next().await;
 
     let network = match msg.from {
       Service::Processor(network) => network,