Register runtime hints for types exposed via PersistenceManagedTypes

[christophstrobl]

By using BindingReflectionHintsRegistrar typical data binding use cases for eg. JPA would be covered.
The current registrar implementation would still miss class references in annotation attributes like in @jakarta.persistence.EntityListeners(MyEntityListener.class) but this could be handled processor.

[sdeleuze]

You can find a draft commit on sdeleuze@gh-29096. It uses as expected BindingReflectionHintsRegistrar to register entities reflection hints.

The part which is more tricky is to decide what Class<?> annotation attributes we support since they will require additional hints. At least for now, I have decided to only support JPA annotations, not implementation specific (like Hibernate) ones.

If I am not mistaken, @ManyToMany, @ManyToOne, @OneToMany and @OneToOne are referencing other entities no need for additional hints there.

It is unclear if @MapKeyClass and ElementCollection will require hints, so I think I prefer to now add it for now.

@Converter can be autoapplied without @Convert via @Converter(autoApply=true) so they should probably added via a dedicated mechanism via the @Converter entry point, not the @Convert one which is optional.

So for now in my draft commit I have added support for @IdClass and @EntityListeners which looks to me a reasonable starting point, with the plan to add more support on popular enough features raised by users or our own tests.

@snicoll @christophstrobl @schauder Please let me know if this is ok from your POV or if this should be refined.

[sdeleuze]

I just checked that @Converter classes are properly scanned by PersistenceManagedTypesScanner and they were supported in Spring Native so I will likely add similar support via this issue. Please let me know if you see other points to refine.