Refactor session request events

[Planlos5000]

Currently we have the following events for the session requests

• REQUEST_CREATED
• REQUEST_UPDATED

The REQUEST_CREATED event is sent when a new session request is created. It sends the created session request.
The REQUEST_UPDATED event is sent when a session request is updated. It sends the updated session request.

We want to have the following events

• REQUEST_CREATED
• REQUEST_UPDATED

The REQUEST_CREATED event is sent, when a session request is created. It sends the user id of the created session request.
The REQUEST_UPDATED event is sent, when a session request is updated. It sends the user id of the updated session request.