Add optimistic locking to hibernate entities

[mpostelnicu]

Hibernate/JPA has built-in support for optimistic (and pessimistic) locking.
Optimistic locking is easy to enable and can improve data quality by informing the user a version of the edited data has been changed. Even though in this case the other user will lose all data that she is trying to save, having this check in addition to autosave is not going to lead to major data loss and will provide critical info for user about content being edited by someone else before her save.
https://www.baeldung.com/jpa-optimistic-locking