LU-16110 lprocfs: make job_stats and rename_stats valid YAML

LU-16110 lprocfs: make job_stats and rename_stats valid YAML

Adjust the format of job_stats and rename_stats to make
them valid YAML.  This fixes the output to correctly indent
the items to follow YAML formatting rules.

Add a test case to verify the format of these params is valid
YAML to avoid other errors being introduced in the future.

Signed-off-by: Lei Feng <flei@whamcloud.com>
Change-Id: Idca36621241e97ff87f8ab0448f3c5604057a460
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/48417
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Li Xi <lixi@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>