Fix DataNotificationManager documentation

[petrovWF]

This documentations contains false information(and it can be misleading) for example:
/// To obtain an instance use serviceLocator.get<NotificationsManager>()

This is not correct and should be
/// To obtain an instance use serviceLocator.get<NotificationsConsumer>()

Also we should register DataNotificationManager instance with the serviceLocator..

If we implement this changes please consider changing the logs inside DataNotificationManager that contains:
NotificationManager into NotificationConsumer..