Pass the merged Integration settings and Persistence Unit properties to buildBootstrapServiceRegistry

The EntityManagerFactoryBuilderImpl calls the buildBootstrapServiceRegistry like this:

It would be better if we did it like this:

This way, we can use the PersistenceUnit properties as well, when scanning for an IntegratorProvider.

Currently, passing the IntegratorProvider works only in Spring, not in Java EE applications using the persistence.xml configuration file.