Allow mapping of Hibernate constraint violations

[Brutus5000]

Hibernate generates very generic exceptions when you hit constraints i.e. unique column constraint. This result in very generic error response in Elide.

Desired Behavior

I want to be able to swap the nested ConstraintViolation with a proper business exception that returns proper error codes etc.

Current Behavior

Statuscode 423 Locked is returned with the generic text "could not execute statement".

Possible Solution

I can give Elide a Map<String, Function<ConstraintViolation, Throwable>> where the keys are the names of the constraint hit.
If a ConstraintViolation occurs, Elide will lookup the constraint name and if it finds one, will map the exception by calling the function from the map value.
I would implement this error mapping in the flush method of AbstractJpaTransaction. Not sure yet how to pass the map in there.

This would be a JpaDatastore only solution. Ideas for more general solutions are welcome.

Context

I'm trying to improve error handling for our frontend people.