Add JSON Schema validation error reporting

:Release Notes:
Added calls of schemaInfo->m_errHandler's functions when validation
against schema failed in C API. Extended JValidation::isValid() API to
provide error handling. Added validation error calls on CPP parsing API.

:Detailed Notes:

:Testing Performed:
Unit tests with valgrind

:QA Notes:

:Issues Addressed:
[GF-43955] pbnjson: Provide information about validation error

Open-webOS-DCO-1.0-Signed-off-by: Mykola Kryvonos <mykola.kryvonos@lge.com>

Change-Id: Ic78b60c7baeed756089ec1f9bd3446c62fa4e8e1
Reviewed-on: https://g2g.palm.com/3874
Reviewed-by: Build Verification
Reviewed-by: Mykola Kryvonos <mykola.kryvonos@lge.com>
Tested-by: Mykola Kryvonos <mykola.kryvonos@lge.com>
Reviewed-by: Keith Derrick <keith.derrick@lge.com>