refactor: optimize the extension watch parameters to always be of real type

[guqing]

What type of PR is this?

/kind improvement /area core /milestone 2.17.x

What this PR does / why we need it:

优化触发 Extension Watch 方法（onAdd/onUpdate/onDelete）时的参数始终为真实类型避免使用时进行类型转换

Does this PR introduce a user-facing change?

None

[f2c-ci-robot[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JohnNiang

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/halo-dev/halo/blob/main/OWNERS)~~ [JohnNiang] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 56.94%. Comparing base (bc10336) to head (984e3cb). Report is 18 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #6180 +/- ## ============================================ + Coverage 54.51% 56.94% +2.43% - Complexity 3523 3707 +184 ============================================ Files 646 652 +6 Lines 21862 22038 +176 Branches 1528 1537 +9 ============================================ + Hits 11917 12549 +632 + Misses 9328 8882 -446 + Partials 617 607 -10 ```

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