feat(number-keyboard): 新增 confirm 事件

[eiinu]

这个 PR 做了什么? (简要描述所做更改)

这个 PR 是什么类型? (至少选择一个)

• [ ] feat: 新特性提交
• [ ] fix: bug 修复
• [ ] docs: 文档改进
• [ ] style: 组件样式/交互改进
• [ ] type: 类型定义更新
• [ ] perf: 性能、包体积优化
• [ ] refactor: 代码重构、代码风格优化
• [ ] test: 测试用例
• [ ] chore(deps): 依赖升级
• [ ] chore(demo): 演示代码改进
• [ ] chore(locale): 国际化改进
• [ ] chore: 其他改动（是关于什么的改动？）

这个 PR 涉及以下平台:

• [ ] NutUI H5 @nutui/nutui
• [ ] NutUI Taro @nutui/nutui-taro

这个 PR 是否已自测:

• [ ] 自测 Vite 脚手架使用 测试仓库
• [ ] 自测 Taro 脚手架使用小程序 & Taro-H5 测试仓库

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 93.75000% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 83.92%. Comparing base (499f576) to head (61c768f).

Files	Patch %	Lines
src/packages/__VUE/numberkeyboard/index.vue	93.75%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## v4 #3059 +/- ## ========================================== - Coverage 83.96% 83.92% -0.05% ========================================== Files 223 223 Lines 23055 23039 -16 Branches 2477 2477 ========================================== - Hits 19358 19335 -23 - Misses 3679 3686 +7 Partials 18 18 ```

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