chore: export some useful utils func

[moayuisuda]

Checklist

• npm test passes
• commit message follows commit guidelines

Description of change

1. 导出一些常用的工具方法，调整了工具函数的目录结构
2. 简化 dataOf 函数，支持直接传入 element 得到原始数据

import { dataOf } from '@antv/g2'
...
chart.on('plot:click', e => {
  console.log(dataOf(e.target)) // do something with original data
})

[petercat-assistant]

Walkthrough

本次PR主要导出了一些常用的工具函数，并调整了工具函数的目录结构。此外，简化了dataOf函数，使其支持直接传入元素以获取原始数据。

Changes

文件	概要
tests/unit/utils/helper.test.ts	添加了groupNameOf和dataOf函数的单元测试。
src/api/runtime.ts	添加了关于取消渲染的注释。
src/exports.ts	导出了dataOf和groupNameOf函数。
src/interaction/event.ts	标记dataOf函数为已弃用，建议使用新的实现。
src/interaction/tooltip.ts	移除了groupNameOf函数的旧实现，改为从utils/helper导入。
src/utils/helper.ts	添加了getViewFromElement、dataOf和groupNameOf函数。

[coveralls]

Pull Request Test Coverage Report for Build 13854422832

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 39 of 42 (92.86%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.007%) to 86.697%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/utils/helper.ts	34	37	91.89%

Totals
Change from base Build 13853281457:	0.007%
Covered Lines:	10630
Relevant Lines:	11886

---

💛 - Coveralls

[hustcc]

另外一起看看，这类 api，文档上怎么透出。

[moayuisuda]

另外一起看看，这类 api，文档上怎么透出。

可以像自定义 legend 那样写一个自定义 tooltip 的例子，实际场景里说明下怎么用这些 utils