Restructuring of logging functionality; implementation of position logging for components (not only actors)

Ready to merge! Fixed the problems that held up the MR and more.

Closes #53

• Addition of new functionality:
  • Logging the position of components with adjustable frequency (added how-to to wiki-entry "Logging")
  • Actor positions can still be logged (under the hood handled by logging the root component) but more importantly individual components can be logged. This is vital for logging the position of the VRPawn because only the Head-component is moves with the HMD not the actor "as a whole"
• Moved existing functionality to new classes:
  • Moved BP-callable functions to BPLoggingLibrary (left existing functions in place, marked as deprecated, to not break existing BPs)
  • Moved c++-only functions to LoggingUtils or LogObject

Next step will be position logging of gaze tracking data(in new branch)