Add tiflash supported pushdown for vector functions

[JaySon-Huang]

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• master (the latest development version)
• v8.4 (TiDB 8.4 versions)
• v8.3 (TiDB 8.3 versions)
• v8.2 (TiDB 8.2 versions)
• v8.1 (TiDB 8.1 versions)
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• v7.1 (TiDB 7.1 versions)
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• v6.1 (TiDB 6.1 versions)
• v5.4 (TiDB 5.4 versions)
• v5.3 (TiDB 5.3 versions)

What is the related PR or file link(s)?

• This PR is translated from: Add tiflash supported pushdown for vector functions docs#19194
• Other reference link(s): TiDB vector search doc #18502, expression: Add vector functions tidb#55021

Do your changes match any of the following descriptions?

• Delete files
• Change aliases
• Need modification after applied to another branch
• Might cause conflicts after applied to another branch

[JaySon-Huang]

/cc @EricZequan @breezewish

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-10-28 07:49:48.564538008 +0000 UTC m=+249701.403693555: ☑️ agreed by qiancai.
• 2024-10-28 07:52:34.078300461 +0000 UTC m=+249866.917456007: ☑️ agreed by Oreoxmt.

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[qiancai]

/approve

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qiancai

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[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.4: #18915.