feat(pie): optimize spider

[pearmini]

Spider

close: #6264

• 添加并且优化了 4.0 的饼图 label 布局算法：https://github.com/antvis/G2/blob/master/src/geometry/label/layout/pie/util.ts
• 当 label 过多的时候会自动隐藏
• 截图更新是因为改变了 path 的绘制顺序，视觉上没有区别。

案例

Before	After

export function mockPieSpider(): G2Spec {
  return {
    type: 'interval',
    data: [
      { type: '微博', value: 93.33 },
      { type: '其他', value: 6.67 },
      { type: '论坛', value: 4.77 },
      { type: '网站', value: 1.44 },
      { type: '微信', value: 1.12 },
      { type: '客户端', value: 1.05 },
      { type: '新闻', value: 0.81 },
      { type: '视频', value: 0.39 },
      { type: '博客', value: 0.37 },
      { type: '报刊', value: 0.17 },
    ],
    encode: {
      y: 'value',
      color: 'type',
    },
    labels: [
      {
        position: 'spider',
        text: (obj) => `${obj.type} (${obj.value})`,
      },
    ],
    transform: [{ type: 'stackY' }],
    coordinate: { type: 'theta' },
  };
}

TODO

• code
• test
• example

[coveralls]

Pull Request Test Coverage Report for Build 9953439864

Details

• 98 of 101 (97.03%) changed or added relevant lines in 4 files are covered.
• 4 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.02%) to 86.604%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/shape/text/advance.ts	35	38	92.11%

Files with Coverage Reduction	New Missed Lines	%
src/shape/text/advance.ts	4	89.63%

Totals
Change from base Build 9902373963:	0.02%
Covered Lines:	10518
Relevant Lines:	11764

---

💛 - Coveralls