Implement page function on "search" and add test code

:Release Notes:
Implement page function on "search".
Extend page test on "search" to verify changed code.

:Detailed Notes:
Revised nextPage function to return next page id.
Moved cursor position to page id provided in query as following step.
  1. Find item "_id" which is equal to page id iteratively.
  2. If found, set begin/last position and next page

:Testing Performed:
Standard DB8 test suite extended to include tests aimed at verifying
the newly added code.

:QA Notes:

:Issues Addressed:
[GF-7045] DB8: Page function is not implemented on "search"

Open-webOS-DCO-1.0-Signed-off-by: kyouhyun.hwang <kyouhyun.hwang@lge.com>

Change-Id: Ia2cdd71404449ce59577c35df5e8be8b2bd00052
Reviewed-on: https://g2g.palm.com/2960
Reviewed-by: Build Verification
Reviewed-by: Kyouhyun Hwang <kyouhyun.hwang@lge.com>
Tested-by: Kyouhyun Hwang <kyouhyun.hwang@lge.com>
Reviewed-by: Roger Stringer <roger.stringer@lge.com>