fix: allow updating entity with object relation
This PR simplifies the way we retrieve the new data after an update. Instead of relying on the returned eid from the transactions, we simply use the one passed as parameter.
When updating entities with relations as object, the transaction would return the id of the subject entity, which would then break the getOne call.
Example situation:
Editing relation Museum is_in City
from City. The transaction call would return the id of the Museum. That eid would then be used in the call getOne("City", eidMuseum)
.