Add closure support for elements of address

[dereuromark]

    $this->addBehavior('Geo.Geocoder', ['address' => ['street', 'postal_code', 'city', function (Event $entity) {
        if ($entity->country && $entity->country->id && $entity->country_id === $entity->country->id) {
            return $entity->country->name;
        }
        if ($entity->get('country_name')) {
            return $entity->get('country_name');
        }

        if ($entity->country_id) {
            $country = $this->Countries->get($entity->country_id);
            return $country->name;
        }

        return null;
    }]]);