Moving diagnostics into a service (#14832)

* Moving diagnostics into a service

* Fixing golint checks

* Fixing tests

* Renaming from diagnostics to telemetry

* Adding missing files

* Initializing telemetry earlier in the server startup

* Fixing tests

* Adding a log for the telemetryID initialization error

* Addressing PR review comments

* Fixing merge problem

* Removing some extra Diagnostics mentions

* Making tests pass

app/notification_push.go

@@ -332,7 +332,7 @@ func (s *Server) StopPushNotificationsHubWorkers() {
 }
 
 func (a *App) sendToPushProxy(msg *model.PushNotification, session *model.Session) error {
-	msg.ServerId = a.DiagnosticId()
+	msg.ServerId = a.TelemetryId()
 
 	a.NotificationsLog().Info("Notification will be sent",
 		mlog.String("ackId", msg.AckId),