PersistentEntities should only be created for user class in case of proxy instance.

[christophstrobl]

Build time generated proxy classes should be unpacked to only create and cache PersistentEntity instances for the target user class. This is necessary because generated instances may be picked up during the entity scan potentially polluting the cache within the MappingContext.
The computed PersistentEntity instance is to be cache for both the proxy and user key.

Sample:

// user class
public class Coupon { }

// proxy
public class Coupon$$SpringProxy$873fa2e extends Coupon implements LazyLoadingProxy, SpringProxy, Advised, _AdvisedSupportAware { }