I've tried to use/add the audit info to all events I could see/find.
This makes this PR necessarily huge, because we do store quite a few
events.
I realise it might not be complete yet, but tests
run green, and I think we now have a pattern to follow for other events.
### What
Adds `createdByUserId` to all events exposed by unleash. In addition
this PR updates all tests and usages of the methods in this codebase to
include the required number.
