fio removing discovery & multithroughput (#575)

* FIO platform

* Removing discovery & multithroughput, removing job file from FioExecutor.

* PERF IO FIO OLTP changes

* documentation changes, OLTP profile changes.

* More block sizes for OLTP profile.

* Moving parameters to command line.

* Using duration.totalseconds.

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Co-authored-by: saibulusu <saibulusu@microsoft.com>

Author: saibulusu