LU-16501 lod: add qos_ost_weights to debugfs

LU-16501 lod: add qos_ost_weights to debugfs

The patch adds files qos_ost_weights and qos_mdt_weights
at lod directory in debugfs. File qos_ost_weights would be
also added for each OST pool in a new directory lod/pool.

    lod.<fsname>-MDT*-mdtlov.qos_mdt_weights
    lod.<fsname>-MDT*-mdtlov.qos_ost_weights
    lod.<fsname>-MDT*-mdtlov.pool.<pool>.qos_ost_weights

These files provide target and server weights, penalties and other
data needed to debug QOS allocator imbalance issues in YAML:

- { ost_idx: 0, tgt_weight: 1137680, tgt_penalty: 0,
    tgt_penalty_per_obj: 115544, tgt_avail: 1137680,
    tgt_last_used: 1677104866, svr_nid: 192.168.100.31@tcp,
    svr_bavail: 2070560, svr_iavail: 1, svr_penalty: 0,
    svr_penalty_per_obj: 52572, svr_last_used: 1677104866 }

Writing to qos_ost_weights/qos_mdt_weights would cause
resetting of tgt_weight, tgt_penaly and svr_penalty.

The patch also adds sanity_205f to check YAML output.

Signed-off-by: Sergey Cheremencev <scherementsev@ddn.com>
Change-Id: I27e3f5abeb2f31b1c445658be035ec7e76c1572e
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/50074
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>