Provide an option to skip foreign key creation for ConstraintMode.PROVIDER_DEFAULT

Foreign key has obvious disadvantages, and the only one advantage is Referential Integrity, which is a bit unworthy for ORM. hibernate should provide a configurable option in AvailableSettings to skip foreign key creation for ConstraintMode.PROVIDER_DEFAULT.

https://stackoverflow.com/questions/56693633/how-to-set-default-constraintmode-in-jpa-hibernate