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

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

This patch is the second in a series of patches that implement
functionality for combining reports on size statistics and
includes functionality for reading and recording tables obtained
from different reports in JSON format.
Only affects file size statistics.

Test-Parameters: trivial testlist=sanity-lipe-scan3,sanity-lipe-find3
Signed-off-by: Vitaliy Kuznetsov <vkuznetsov@ddn.com>
Change-Id: I742879e61049e00b98d5f9defd7dabaea85fba0a
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/55047
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>