Adding latex label str to systematic definitions. Adding nuisance pull plotting function.

rdstar/latex_labels/latex_particle_names.py

rdstar/latex_labels/latex_process_labels.py

...s/fitting/dedicated_fit_approach/dedicated_sys_handler.py

...analysis/fitting/dedicated_fit_approach/plotting_tools.py

...ysis/fitting/dedicated_fit_approach/rdstar_systematics.py