Adapt BasicProxyFactoryImpl to be more native-image friendly
This relates to Quarkus issue:
We can easily avoid registering the proxy for reflection by holding a reference to the constructor rather than to the Class instance of the generated proxy. Proxies are generated during augmentation and since each BasicProxyFactoryImpl instance holds a reference to the matching constructor, GraalVM's native-image can figure it out.
This will need to be followed by integration tests in Quarkus.
BTW I suspect this also represents a more general efficiency optimisation.