sixtracklib/common: Added helper functions to impl/particles_api.h to track numerical errors and differences
sixtracklib/common: Added helper functions to impl/particles_api.h to track numerical errors and differences

- Added a function to calculate the element-wise difference between two NS(Particles) instances and store the
  result in a third instance.

- Added a function to find the largest attribute value  in a NS(Particle) instance and returns (optionally)
  the particle index of the particle holding this extreme value

- Added NS(Blocks) based buffer varaintes of these two functions for convenience

SixTrack/SixTrackLib,SixTrack/SixTrackLib,SixTrack/SixTrackLib,SixTrack/SixTrackLib