ttl: ouput TTL comment format when show create table (#39853)

[ti-chi-bot]

This is an automated cherry-pick of #39853

What problem does this PR solve?

Issue Number: close #39852

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:

• YangKeao
• hawkingrei

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[YangKeao]

LGTM

[hawkingrei]

/merge

[ti-chi-bot]

@hawkingrei: /merge in this pull request requires 2 approval(s).

In response to this:

/merge

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[hawkingrei]

/merge

[ti-chi-bot]

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

Commit hash: e4be489

[YangKeao]

/run-mysql-test

[ti-chi-bot]

@ti-chi-bot: Your PR was out of date, I have automatically updated it for you.

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.