Update performance test to allow multiple runs and change some default values
Update performance test to allow multiple runs and change some default values

More clients will cause more stress than more files so increase number of clients and decrease number of files to get the same amount of data written.

tusdotnet/tusdotnet,tusdotnet/tusdotnet,tusdotnet/tusdotnet,smatsson/tusdotnet,smatsson/tusdotnet,tusdotnet/tusdotnet