CBQE-1900: tuq: add negative test for unnest+alias

Change-Id: If3cae4a03b8c61fbe7788a6e790619b62d7b852f
Reviewed-on: http://review.couchbase.org/32713
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>