CBQE-1957: tuq: add toarray fn test

Change-Id: I16da6d078359d4cd0579f232cc736416626d9224
Reviewed-on: http://review.couchbase.org/33120
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>