Refactor notifications (#2688)

This PR changes the handling of notifications
- removes the `StreamEvent` and `ReadUpdate` stream
- listens on the `OutputRoomEvent` stream in the UserAPI to inform the
SyncAPI about unread notifications
- listens on the `OutputReceiptEvent` stream in the UserAPI to set
receipts/update notifications
- sets the `read_markers` directly from within the internal UserAPI

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

syncapi/syncapi.go

@@ -77,16 +77,6 @@ func AddPublicRoutes(
 		logrus.WithError(err).Panicf("failed to start presence consumer")
 	}
 
-	userAPIStreamEventProducer := &producers.UserAPIStreamEventProducer{
-		JetStream: js,
-		Topic:     cfg.Matrix.JetStream.Prefixed(jetstream.OutputStreamEvent),
-	}
-
-	userAPIReadUpdateProducer := &producers.UserAPIReadProducer{
-		JetStream: js,
-		Topic:     cfg.Matrix.JetStream.Prefixed(jetstream.OutputReadUpdate),
-	}
-
 	keyChangeConsumer := consumers.NewOutputKeyChangeEventConsumer(
 		base.ProcessContext, cfg, cfg.Matrix.JetStream.Prefixed(jetstream.OutputKeyChangeEvent),
 		js, rsAPI, syncDB, notifier,
@@ -98,7 +88,7 @@ func AddPublicRoutes(
 
 	roomConsumer := consumers.NewOutputRoomEventConsumer(
 		base.ProcessContext, cfg, js, syncDB, notifier, streams.PDUStreamProvider,
-		streams.InviteStreamProvider, rsAPI, userAPIStreamEventProducer,
+		streams.InviteStreamProvider, rsAPI,
 	)
 	if err = roomConsumer.Start(); err != nil {
 		logrus.WithError(err).Panicf("failed to start room server consumer")
@@ -106,7 +96,6 @@ func AddPublicRoutes(
 
 	clientConsumer := consumers.NewOutputClientDataConsumer(
 		base.ProcessContext, cfg, js, syncDB, notifier, streams.AccountDataStreamProvider,
-		userAPIReadUpdateProducer,
 	)
 	if err = clientConsumer.Start(); err != nil {
 		logrus.WithError(err).Panicf("failed to start client data consumer")
@@ -135,7 +124,6 @@ func AddPublicRoutes(
 
 	receiptConsumer := consumers.NewOutputReceiptEventConsumer(
 		base.ProcessContext, cfg, js, syncDB, notifier, streams.ReceiptStreamProvider,
-		userAPIReadUpdateProducer,
 	)
 	if err = receiptConsumer.Start(); err != nil {
 		logrus.WithError(err).Panicf("failed to start receipts consumer")