Sorry for late reply, I missed your question somehow.
Datasource listeners cannot do it. They react on changes in the current screen an in the current user session.
The simplest solution in my opinion would be using a screen timer that once in 10…20 seconds checks whether the version of the currently edited entity is still the same in the database. You can use DataManager to load the entity with a minimal view. The entity should implement the Versioned interface.