Add SQL diagnosis rule: threshold check for tikv_append_log_duration

[crazycs520]

Development Task

When Raft append log duration, P99 Value > 500ms, then append an warning in INSPECTION_RESULT table, this may be caused by:

• write disk too slow, check the disk latency.
• It may trigger the RocksDB Write Stall.

Refer

• You can query the tikv_append_log_duration table to get metrics_schema.tikv_append_log_duration value. Here is the related doc.
• You can refer the thresholdCheckInspection implementation in TiDB.

If you have any questions or want to discuss something, you can chat in the sig-dashboard slack channel and @ chenshuang.