Only show approved applications in Tarako queue (bug 1053354)

https://bugzilla.mozilla.org/show_bug.cgi?id=1053354
Looks like it's just the one query with a `JOIN`.

```sql
-- str(AdditionalReview.objects.unreviewed(queue='tarako', approved=True).query)
SELECT `additional_review`.`id`, `additional_review`.`created`,
       `additional_review`.`modified`, `additional_review`.`app_id`,
       `additional_review`.`queue`, `additional_review`.`passed`,
       `additional_review`.`review_completed`
FROM `additional_review`
INNER JOIN `addons` ON ( `additional_review`.`app_id` = `addons`.`id` )
WHERE (`additional_review`.`queue` = tarako
  AND  `addons`.`status` IN (4, 13)
  AND  `additional_review`.`passed` IS NULL)
```