expression: refactor names from VectorHelper to VSInfo

[breezewish]

What problem does this PR solve?

Issue Number: ref #54245

Problem Summary:

What changed and how does it work?

Refactor names to reduce confusion.

Check List

Tests

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

  • I checked and no code files have been changed.

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

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.7203%. Comparing base (e54cc5b) to head (49cec6e).
Report is 59 commits behind head on master.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #58192        +/-   ##
================================================
+ Coverage   73.1811%   73.7203%   +0.5391%     
================================================
  Files          1676       1676                
  Lines        462078     462216       +138     
================================================
+ Hits         338154     340747      +2593     
+ Misses       103155     100746      -2409     
+ Partials      20769      20723        -46     

Flag	Coverage Δ
integration	43.2099% <42.8571%> (?)
unit	72.4270% <100.0000%> (+0.1212%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	52.6910% <ø> (ø)
parser	∅ <ø> (∅)
br	46.0058% <ø> (+0.0240%)	⬆️

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: AilinKid, XuHuaiyu

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Needs approval from an approver in each of these files:

• pkg/expression/OWNERS [XuHuaiyu]
• pkg/planner/OWNERS [AilinKid]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-12-12 04:26:39.353993929 +0000 UTC m=+498989.442796472: ☑️ agreed by AilinKid.
• 2024-12-12 05:54:21.269844301 +0000 UTC m=+504251.358646844: ☑️ agreed by XuHuaiyu.