gtest_dbcore: Add new test for JSON parsing

:Release Notes:
Add test for JSON parsing

:Detailed Notes:
- Test of raw json parser
- Test for json parser to DOM (MojObject)
- Test for database load (MojDb::load)

:Testing Performed:
Compiled locally and tested on a device.

:QA Notes:

:Issues Addressed:
[GF-8333] Optimize use of DB8 to load records

Open-webOS-DCO-1.0-Signed-off-by: Maksym Sditanov <msditanov@luxoft.com>

Change-Id: I8a739f9503ba90c10980f5f9752e316a1c2c6101
Reviewed-on: https://g2g.palm.com/2831
Reviewed-by: Build Verification
Reviewed-by: Maksym Sditanov <msditanov@luxoft.com>
Tested-by: Maksym Sditanov <msditanov@luxoft.com>
Reviewed-by: Roger Stringer <roger.stringer@lge.com>
CMakeLists: remove RPATH after install

:Release Notes:
Remove RPATH in make install target

:Detailed Notes:

:Testing Performed:
Testing on local environment

:QA Notes:

:Issues Addressed:
[GF-5379] db8 package contains absolute paths from build machine

Open-webOS-DCO-1.0-Signed-off-by: Maksym Sditanov <msditanov@luxoft.com>

Change-Id: I9c45debc0610b383a28b10c876468ec408c9b711
Reviewed-on: https://g2g.palm.com/2859
Reviewed-by: Build Verification
Reviewed-by: Maksym Sditanov <msditanov@luxoft.com>
Tested-by: Maksym Sditanov <msditanov@luxoft.com>
Reviewed-by: Roger Stringer <roger.stringer@lge.com>