[update] definition of domain event

[BirgitBader]

(i) This issue has been manually transferred from a former internal repository, as a private repository issue cannot be transferred to a public repository.

Context

Notes from discussion of 2022/07/08:

• domain events can contain the whole data structure. They are still domain events because they have been triggered by an occurrence in the domain that is contained within the domain event.
• Add a decision table / example table when to use what (e.g., log compaction)
• Consumers of data events should not care about the order of events