[MM-57066][MM-57329] Added metrics for all notification stopping points, consolidated categories between metrics and logging (#26799)

* [MM-57066] Add metric counters for notification events

* Some small changes

* Account for Metrics() sometimes being nil

* Fix test (again)

* Fix more tests

* A few changes from testing - added success counter

* Missed a mock

* Lint

* Add feature flag for notification monitoring

server/channels/app/web_broadcast_hooks.go

@@ -86,6 +86,7 @@ func (h *postedAckBroadcastHook) Process(msg *platform.HookedWebSocketEvent, web
 	// This works since we currently do have an order for broadcast hooks, but this probably should be reworked going forward
 	if msg.Get("followers") != nil || msg.Get("mentions") != nil {
 		msg.Add("should_ack", true)
+		incrementWebsocketCounter(webConn)
 		return nil
 	}
 
@@ -107,6 +108,7 @@ func (h *postedAckBroadcastHook) Process(msg *platform.HookedWebSocketEvent, web
 	// Always ACK direct channels
 	if channelType == model.ChannelTypeDirect {
 		msg.Add("should_ack", true)
+		incrementWebsocketCounter(webConn)
 		return nil
 	}
 
@@ -117,11 +119,24 @@ func (h *postedAckBroadcastHook) Process(msg *platform.HookedWebSocketEvent, web
 
 	if len(users) > 0 && slices.Contains(users, webConn.UserId) {
 		msg.Add("should_ack", true)
+		incrementWebsocketCounter(webConn)
 	}
 
 	return nil
 }
 
+func incrementWebsocketCounter(wc *platform.WebConn) {
+	if wc.Platform.Metrics() == nil {
+		return
+	}
+
+	if !wc.Platform.Config().FeatureFlags.NotificationMonitoring {
+		return
+	}
+
+	wc.Platform.Metrics().IncrementNotificationCounter(model.NotificationTypeWebsocket)
+}
+
 // getTypedArg returns a correctly typed hook argument with the given key, reinterpreting the type using JSON encoding
 // if necessary. This is needed because broadcast hook args are JSON encoded in a multi-server environment, and any
 // type information is lost because those types aren't known at decode time.