LU-13366 utils: SEL yaml and copy file support

LU-13366 utils: SEL yaml and copy file support

create a SEL file by a yaml template or by copying the template
from another file (setstripe --yaml and setstripe --copy).

Signed-off-by: Vitaly Fertman <c17818@cray.com>
Change-Id: I001226a9dcfa5706295cef1c13a2e7aeb5c498cc
Reviewed-by: Alexey Lyashkov <c17817@cray.com>
Reviewed-by: Alexander Boyko <c17825@cray.com>
Tested-by: Elena Gryaznova <c17455@cray.com>
Reviewed-on: https://es-gerrit.dev.cray.com/156286
HPE-bug-id: LUS-8039
Reviewed-on: https://review.whamcloud.com/37960
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>