LU-16415 quota: enforce project quota for root

LU-16415 quota: enforce project quota for root

Patch adds an option to enforce project quotas for root.
It is disabled by default, to enable set
osd-ldiskfs.*.quota_slave.root_prj_enable to 1
at each target where you need this option.

Patch also adds sanity-quota_1j to test new feature.

Signed-off-by: Sergey Cheremencev <scherementsev@ddn.com>
Change-Id: I978dc8442235149794f85110309f63bc560defdc
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49460
Reviewed-by: Hongchao Zhang <hongchao@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Shuichi Ihara <sihara@ddn.com>
Tested-by: Maloo <maloo@whamcloud.com>