Improve the event system by adding an extra Event for gNMI-Subscribe to replace the currently used Update Event
Description
After receiving a Notification via gNMI-Subscribe, the controller forwards the contents via RabbitMQ using the Update Event with additional information. This leads to two Update Events being sent, when the change happened as a change of a path value via controller. It would be preferrable to have two different Events being sent when such a change happens. Reasons behind this change are:
- an App might want to only listen to appearing Updates or Subscribe Messages
- an App can differ more easily how to react to an Event and also only once instead of twice because of receiving two Update Events
The new Event could be named like: SubscribeEvent