What version are you running?
3.0.15
What's the URL of the page this enhancement relates to, if any?
/admin/db/notifications/webhooktarget/nnn/
Describe the enhancement and the motivation for it.
The current information provided in the outgoing webhook json is insufficient to determine the user that triggered the webhook. For example, the user who submitted the request would be the one who triggered a review_request_published event. The current submitter field is insufficient since a user may submit a request on behalf of another user. Another example would be the user who changed a request and triggered a review_request_published event.
All events that trigger a webhook have a user behind them that caused the event, and that information should be provided in the data.