Introduce /clock methods

:Release Notes:
Methods (/clock) for working with different clocks in system.

:Detailed Notes:
Additional /clock methods:
- register clock
- set time for clock
- get time for clock
- get time for clock with fallback and possibility of manual override
- synchronization priority
- replaced single quote with double quote in json encoded params
- etc
Note that deprecated API isn't yet tied with new one (they work almost
independently). I.e. setting user time through /time/setSystemTime
wouldn't set "manual" time source. On the other hand setting
/clock/setTime for "manual" time source will set system time in case
of manual mode enabled or absence of any time setting. etc.

:Testing Performed:
Desktop build. Different /clock/getTime and /clock/setTime with
variations of properties for each functionality.

:QA Notes:

:Issues Addressed:
[GF-52639] possibility to replace NTP with other time source

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

Change-Id: If17893535a53a6a14c47c6fdd8a5ff155196e81a
Reviewed-on: https://g2g.palm.com/4143
Reviewed-by: DCO Verification
Reviewed-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Tested-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Reviewed-by: Alekseyev Oleksandr <alekseyev.oleksandr@lge.com>