Differentiate between scheduled/started/finished to monitor the performance of the Load Generator

[PaulWen]

Scheduled = iterations scheduled by the Periodic Schedular Started = iterations actually initiated by placing a HTTP Call to an AcaPy FInished = all the iterations that have been finished

Scheduled and Started differs in case the thread pool responsible for executing the scheduled tasks to start iterations is exhausted as all the threads are currently busy trying to start new iterations.