update systematics

[pkausw]

• for now: re-initialize systematicsObject dictionary in analysisObject for each call of update_systematics
• possible idea for future (better performance?): create function to
• loop through all processes in all categories
• loop through systematics in process
• check if systematic already exists in systematicsObject dictionary (-> analysisObject)
• implement logic to overwrite existing systematics
• implement logic to delete excess processes in systematicObject dictionary
• implement logic to delete excess systematics in systematicObject dictionary