Improve the cost time information display in slow log detail

[crazycs520]

Bug Report

Please answer these questions before submitting your issue. Thanks!

What did you do?

Currently, the cost time information display is such as below:

The problem is it is hard to understand the relationship of so many durations, maybe we can format such as a tree to easy find out the parent-child relationship:

Currently, the relationship is as below:

Query_time
    Parse_time
    Compile_time:
        Rewrite_time:
            Process_subquery_time:
        Optimize_time:
    Wait_TS:
    Cop_time:
        Cop_Process_time:
        Cop_Wait_time: 
    Lock_keys_time:
    Local_latch_wait_time:
    Backoff_time:
    Prewrite_time:
    Wait_prewrite_binlog_time:
    Get_Commit_TS:
    Commit_time:
    Commit_backoff_time
    Resolve_lock_time:
Write_Response_time:
Retry_exec_time:

What version of TiDB Dashboard are you using (./tidb-dashboard --version)?

▶ bin/tidb-dashboard --version
Internal Version:  nightly
Git Commit Hash:   d03c863267595253c2c39c4007849a4baf63ab0f
UTC Build Time:    2020-11-23 09:57:50

[baurine]

fixed by #810 , so we can close it.