*: show start time of multi-schema change sub-jobs

[tangenta]

What problem does this PR solve?

Issue Number: ref #14766

Problem Summary:

What is changed and how it works?

Before this PR:

|     92 | test    | t                    | alter table multi-schema change     | none         |         2 |       88 |         0 | 2023-05-25 15:24:06 | 2023-05-25 15:24:06 | 2023-05-25 15:24:16 | synced |
|     92 | test    | t                    | add index /* subjob */ /* ingest */ | public       |         2 |       88 |         3 | NULL                | NULL                | NULL                | done   |
|     92 | test    | t                    | add index /* subjob */ /* ingest */ | public       |         2 |       88 |         3 | NULL                | NULL                | NULL                | done   |
|     92 | test    | t                    | add index /* subjob */ /* ingest */ | public       |         2 |       88 |         3 | NULL                | NULL                | NULL                | done   |

After this PR:

|     92 | test    | t                    | alter table multi-schema change     | none         |         2 |       88 |         0 | 2023-05-25 15:24:06 | 2023-05-25 15:24:06 | 2023-05-25 15:24:16 | synced |
|     92 | test    | t                    | add index /* subjob */ /* ingest */ | public       |         2 |       88 |         3 | 2023-05-25 15:24:06 | 2023-05-25 15:24:06 | 2023-05-25 15:24:16 | done   |
|     92 | test    | t                    | add index /* subjob */ /* ingest */ | public       |         2 |       88 |         3 | 2023-05-25 15:24:06 | 2023-05-25 15:24:10 | 2023-05-25 15:24:16 | done   |
|     92 | test    | t                    | add index /* subjob */ /* ingest */ | public       |         2 |       88 |         3 | 2023-05-25 15:24:06 | 2023-05-25 15:24:14 | 2023-05-25 15:24:16 | done   |

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• crazycs520
• zimulala

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[zimulala]

LGTM

[tangenta]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 6967dda