Add API to verify jvalue against schema

:Release Notes:
Add C API jvalue_check_schema
Add CPP API JValidator::isValid
Remove a few low-level public C API

:Detailed Notes:
Add APIs to validate jvalue against schema

:Testing Performed:
Internal unit tests were extended to cover new functional
Internal unit tests were successully passed. Tests were run with
control of memory errors

:QA Notes:

:Issues Addressed:
[GF-2836] Validation of json objects against schemas in pbnjson

Open-webOS-DCO-1.0-Signed-off-by: Alekseyev Oleksandr <alekseyev.oleksandr@lge.com>

Change-Id: I0693cfe62e74e293453d45a9b72ec71b70cb8f87
Reviewed-on: https://g2g.palm.com/2854
Reviewed-by: Build Verification
Reviewed-by: Alekseyev Oleksandr <alekseyev.oleksandr@lge.com>
Tested-by: Alekseyev Oleksandr <alekseyev.oleksandr@lge.com>
Reviewed-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>