CBQE-0: Optimize code for tuq and 2i

This change tries to capture data generation to common class. To be used in 2i and tuq tests. Also, we reduce code for tuq

Change-Id: If0563bb428cee077e6bb6c15b7312d2301eac3e0
Reviewed-on: http://review.couchbase.org/43818
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>