Re-factor NTP request to be asynchronous

:Release Notes:
Fix issue when luna-sysservice hangs while processing NTP request.

:Detailed Notes:
Add dedicated object that serves as a NTP clock source.

:Testing Performed:
Verified in desktop and qemux86 builds

:QA Notes:

:Issues Addressed:
[GF-55212] synchronous approach for NTP sync. blocks luna-sysservice

Open-webOS-DCO-1.0-Signed-off-by: Nikolay Orliuk <nikolay.orliuk@lge.com>

Change-Id: I0be428b91e3da4dc7f800d8be32a4b4f5593d6df
Reviewed-on: https://g2g.palm.com/4218
Reviewed-by: DCO Verification
Reviewed-by: Keith Derrick <keith.derrick@lge.com>
Tested-by: Keith Derrick <keith.derrick@lge.com>