EX-9609 lipe: Add sorting to reports by directory sizes

EX-9609 lipe: Add sorting to reports by directory sizes

This patch does not change format the display of tables
in directory reports. This patch adds sorting to the directory
size report.  This patch also sorts the TOP-X rating table.
Sorting occurs in descending order of size. Sorting is done
based on the allocated size.

Test-Parameters: trivial testlist=sanity-lipe-scan3,sanity-lipe-find3
Signed-off-by: Vitaliy Kuznetsov <vkuznetsov@ddn.com>
Change-Id: I5d641660d7bf33cedb27612c04d1a7de43d78c75
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/55395
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alexandre Ioffe <aioffe@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>