Implementing #750. Added necessary changes to job class and wrapperjob so the...

Implementing #750. Added necessary changes to job class and wrapperjob so the TOTAL_STATS file is not written when the job is sent as HELD, instead, the TOTAL_STAS will be written when the job changes from HELD to QUEUING. Also, added some helpers in the run_experiment function to clean up code. Added typing assistance.