storage: Add vector search metrics

[Lloyd-Pottiger]

What problem does this PR solve?

Issue Number: ref #9032

Problem Summary:

What is changed and how it works?

Pick https://github.com/tidbcloud/tiflash-cse/pull/190

storage: Add vector search metrics

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

None

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: breezewish, JinheLin

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• OWNERS [JinheLin,breezewish]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-08-26 03:21:50.198802715 +0000 UTC m=+754105.333252831: ☑️ agreed by breezewish.
• 2024-08-26 03:36:15.289515838 +0000 UTC m=+754970.423965961: ☑️ agreed by JinheLin.