Consider further specializing AbstractAugmentable

Keyed lists provide a combination of Augmentable and Identifiable. We should be able to specialize AbstractIdentifiableAugmentable, so that we end up sharing the same implementation:

package org.opendaylight.yangtools.yang.binding;

@Beta
public abstract AbstractIdentifiableAugmentable<I extends Identifier<T>, T extends Augmentable<T> & Identifiable<I>>
    extends AbstractAugmentable<T> implements Identifiable<I> {

    private final @NonNull I key;


    @Override
    public final I key() {
        return key;
    }
}

generated classes can then take advantage of it and overlay this with an interface-specific specialized implementation. This should result in the number of runtime-visible effective implementations going down, hopefully making JIT's life easier.