Add BeanManager.createDecorator() and BeanManager.createInterceptor()

It is unclear from the specification whether the BeanManager.createBean() method should ever return an implementation of the Decorator or Interceptor interface.

Method parameters of the createBean() method provide all the necessary information for constructing a Decorator implementation. Therefore, IMHO the method should return a container-provided Decorator implementation if the set of stereotypes returned by BeanAttributes.getStereotypes contains javax.decorator.Decorator.

On the other hand, Interceptors do not fit this model because the AnnotatedType of the bean class is not available to the method and using the reflection API to scan the bean class directly would not be consistent with the rest of the specification.