CBQE-1900: tuq: add test join+unnest+alias

Change-Id: If3c89edbabb0365e3dd067018ea72628470e6981
Reviewed-on: http://review.couchbase.org/32717
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>