Resolve "refactor(core): homogenise all timestamping mechanism"

Description

Refactor code in order to homogenise all timestamping mechanism.

Closes #1081 (closed)

How to test it?

Run all tests on Windows and Linux environment.
Examples that use some services that have been impacted by refactoring:

• ExVideoRecorder
• ExVideoTracking
• ExDetectCamMotion
• ExRGBDManualAR
• ExSolvePnP
• ExFrameByFrame
• ExStereoARCV
• ExIgtl
• ExRegistration
• (ExRealSense)
• (ExOpenvslam)
• (ExRGBDImageMasking)

And also the tutorial Tuto17SimpleAR.