Add AnnotationDescriptor#createUsage for creating "defaulted" usages

[sebersole]

Specifically for creating AnnotationUsage references with all default values applied.

interface AnnotationDescriptor<A extends Annotation> extends AnnotationTarget {
    ...

    /**
     * Create a usage of this annotation with all attribute values defaulted.
     */
    AnnotationUsage<A> createUsage(AnnotationTarget target);

    /**
     * Create a usage of this annotation with all attribute values defaulted, allowing customization prior to return
     */
    AnnotationUsage<A> createUsage(AnnotationTarget target, Consumer<AnnotationUsage<A>> initializer);
}