CBQE-1531: add expressions tests to query tool

Change-Id: Ibe41054bd3625da9108113216639821c79ae756c
Reviewed-on: http://review.couchbase.org/29272
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>