planner, json: restore cast flag after substitute column in cast (#39997)

[ti-chi-bot]

This is an automated cherry-pick of #39997

Signed-off-by: YangKeao yangkeao@chunibyo.icu

What problem does this PR solve?

Issue Number: close #39806

Problem Summary:

json functions use a flag mysql.ParseToJSONFlag to mark whether the castStringAsJson function should try to parse the string as a json, or simply convert the string to a json string. For example, with this flag, abcd is not a valid json, and will return an error. Without this flag, abcd will be casted to "abcd".

What is changed and how it works?

Check List

Tests

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

Release note

Fix the issue that predicate push down could result in json format error with `json_object` function

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• hawkingrei
• xhebox

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[YangKeao]

/retest

[xhebox]

/merge

[ti-chi-bot]

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

Commit hash: c7dc4f4da3859f6f32d4ac7a7353b35dca949ea8

[YangKeao]

/retest

[YangKeao]

/retest

[YangKeao]

Wait for #44233

[YangKeao]

/merge

[ti-chi-bot]

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

Commit hash: 65968f9