Add "substring" search in filter clause

:Release Notes:
Add "%%" operator in filter to search "substring",
and test case.

:Detailed Notes:
- Add OpSubString enum type to MojDbQuery::CompOp;
- Modify MojDbQuery::addCluase();
- Add findSubString() to MojDbQueryFilter;
- Add strToUpper() to MojDbTextUtils;
- Add "%%" operator to filter clause in MojDbServiceSchemas;
- Add test case for "substring" search to MojDbQueryFilterTest;

:Testing Performed:
tested on build

:QA Notes:

:Issues Addressed:
[GF-37501] DB8: Add substring search in filter

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

Change-Id: I1b96375329fdde9ae52e44cc25d79cd79a4ac998
Reviewed-on: https://g2g.palm.com/3468
Reviewed-by: Build Verification
Reviewed-by: Kyouhyun Hwang <kyouhyun.hwang@lge.com>
Tested-by: Kyouhyun Hwang <kyouhyun.hwang@lge.com>
Reviewed-by: Igor Kuksyuk <ikuksyuk@luxoft.com>
Reviewed-by: Roger Stringer <roger.stringer@lge.com>