EX-9121 lipe: Add functionality for parsing ranges from JSON

EX-9121 lipe: Add functionality for parsing ranges from JSON

This patch is the third in a series of patches that implement
functionality for combining size statistics reports and includes
functionality for reading and saving the resulting ranges in tables
obtained from different reports in JSON format.
Only affects file size statistics and this patch is the final one
for reports on file size statistics.

Test-Parameters: trivial testlist=sanity-lipe-scan3,sanity-lipe-find3
Signed-off-by: Vitaliy Kuznetsov <vkuznetsov@ddn.com>
Change-Id: I9714f5ea970b103652f7714c93d76be2549ad3b8
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/55048
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>