LU-8721 tests: add parallel-scale fio test

LU-8721 tests: add parallel-scale fio test

Patch adds parallel-scale fio test.

Fio (https://git.kernel.org/pub/scm/linux/kernel/git/axboe/fio.git)
is a flexible generator of I/O of various modes: memory mapped,
multithreaded, asynchronous read/write I/O, etc.
Any fio job file including those created by third party can be
supplied via $fio_jobFile.
By default, random 128mb write
is performed.

Test-Parameters: trivial envdefinitions=ONLY=fio testlist=parallel-scale
Seagate-bug-id: MRP-3707
Signed-off-by: Elena Gryaznova <elena.gryaznova@seagate.com>
Reviewed-by: Vladimir Saveliev <vladimir.saveliev@seagate.com>
Reviewed-by: Alexander Lezhoev <alexander.lezhoev@seagate.com>
Change-Id: I36b471e47e366caae5709f109c28ba57c89f22c7
Reviewed-on: https://review.whamcloud.com/23226
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Vladimir Saveliev <c17830@cray.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>