feat: html label supported

[hustcc]

• fixed 【特性】label 数据标签支持富文本格式 #5133
• demo
• document
• default theme 等 G 更新版本，即可自动实现。
• test

{
  type: 'interval',
  transform: [{ type: 'sortX', by: 'y', reverse: true }],
  data: {
    type: 'fetch',
    value: 'data/alphabet.csv',
  },
  axis: {
    y: { labelFormatter: '.0%' },
  },
  encode: {
    x: 'letter',
    y: 'frequency',
    color: 'steelblue',
  },
  labels: [
    {
      text: 'frequency',
      transform: [
        {
          type: 'overlapHide',
        },
      ],
      className: 'alphabet-labels',
      render: (
        _,
        datum,
      ) => `<div style="left:-50%;top:-16px;position:relative;font-size:12px;">
        <span style="color: blue">${
          datum.letter
        }</span>:<span style="color: black">${datum.frequency.toFixed(
        2,
      )}</span>
      </div>`,
    },
  ],
}

[hustcc]