EX-8130 lipe: Add functions to create a rating

EX-8130 lipe: Add functions to create a rating

This patch adds new functionality to directory statistics
for working with a ranking table for the largest
directories (like TOP 100).

The creation of a structure for storing the rating occurs
after the lipe_scan3 scan is completed. The number of
objects in the structure is determined before lipe_scan3
is launched by the default value or by the user in lipe_find3
via the -top-rating option and is not expanded while lipe_scan3
is running. Adding new objects to the heap works by the logic
of replacing the object with the smallest size in the heap with
a new object if its size is larger. Adding objects to the heap
occurs when printing the results about the directory sizes,
since only in this case do we know the final sizes of the directories.

Test-Parameters: trivial
Signed-off-by: Vitaliy Kuznetsov <vkuznetsov@ddn.com>
Change-Id: Ie4a449fe69022716232638e0f856a10850403831
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/53959
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>