refactor: Rename domain properties to semantic type

[dominikriemer]

Purpose

For better clarity, rename domainProperties to semanticType in the EventProperty model.
Semantic types are now stored as a string instead of a List<URI>.
Old usages of domainProperties should still work and have been marked as deprecated.
We should also change these in the Python and Go client.

Remarks

PR introduces (a) breaking change(s): no

PR introduces (a) deprecation(s): yes

• Use semanticType instead of domainProperties to assign a semantic type to event properties.