Version

5.4.3

Link to Minimal Reproduction

https://echarts.apache.org/examples/en/editor.html?code=LYTwwgFghgTgLgOgM4QPYHcAyqoBMCWAdgOYAUAlANwBQAJAsQKZykBKA8uwCoD6ACgEEuACQAEAalEByAPS4ocKDKhIkzGU1QyAqgGUBCAFZJUhKQBpRAMwCuhAMZx8p0aRtIoAKROFyogN7UoqKgkLCIEPi4jNh4RGRUQaKM9tDwSAgwjMT4SHCMMACyUAAOpFJ6Ahai7l4-loHBwQIANioA1lAAXAFJTaItjFZwPQC0AIwAzOPmfU1wqCU9AEwArLP9wehRcBA946tzAL4bTcJQ6FD4-D2Nm4PDY-PjAAyn_QtLossAHO9N21wux6h36JzmUj4NgKC1ErHw9lQUluc2CDxGolGAHYAGz_YKfFZ41GiQHA77HJJHRLBRZOFwAXl6H3wcEGKM2onyAA8MRV9KI-IsbG16YRRABRPL4YAKRhIVzLF7jZbkCwkpA2ABGPL5ABEFFBrDBUMBSeh0Ah7IxCJqMsRUAA3dWczValpEdo9KQQOBwJYyGQWy3W23uBhOmQlRbyuByQ3xxRqOAZX3AFou-5DPkwfDEX1SY7_BaoFpOL53D654hMGDe1mMYCZ_ooDB6xhtEA9N4kuAwKC21nOQh6mz9sXdhDLItzR25GxQFrFCu9kAlRjekr4FKMbZqZtNdHe9EH4L2OUO3PynoAbSkAhKJUGSGqUnY_ZI8tffEYsBfAF0ZxbAptyQW8SUrTZCCgYAN2kSpBUWKUnFlfIX3xeY1zgqRZRKU8mhNGCej7aEMOCXDvUqfDgkbEpoCQXIOU5Q8oC1DsmOYppW3QYiYGhEkwQE0RwU4-RFHAzjgn8URoNg71WlYmCoGqR1F2heTH2fKRhLIpppNk7CFKQToVLU7D3wHJgXx0oSpJkmDsK4RhuRUUyWnU6Qfz_bSjiEwDOV8_p_OEmhyPANJEGTdgSjFUg6WHRJqUoIA

Steps to Reproduce

visualMap piecewise encoding for categories does not work for series type 'map'

myChart.showLoading();
$.get(ROOT_PATH + '/data/asset/geo/USA.json', function (usaJson) {
  myChart.hideLoading();
  echarts.registerMap('USA', usaJson, {
    Alaska: {
      left: -131,
      top: 25,
      width: 15
    },
    Hawaii: {
      left: -110,
      top: 28,
      width: 5
    },
    'Puerto Rico': {
      left: -76,
      top: 26,
      width: 2
    }
  });
  option = {
    title: {
      text: 'USA Population Estimates (2012)',
      subtext: 'Data from www.census.gov',
      sublink: 'http://www.census.gov/popest/data/datasets.html',
      left: 'right'
    },
    tooltip: {
      trigger: 'item',
      showDelay: 0,
      transitionDuration: 0.2
    },
    visualMap: {
      type: 'piecewise',
      left: 'left',
      categories: ['Apples', 'Oranges', 'Pears']
    },
    series: [
      {
        name: 'USA PopEstimates',
        type: 'map',
        roam: true,
        map: 'USA',
        emphasis: {
          label: {
            show: true
          }
        },
        data: [
          { name: 'Alabama', value: 'Apples' },
          { name: 'Alaska', value: 'Oranges' },
          { name: 'Texas', value: 'Pears' }
        ]
      }
    ]
  };
  myChart.setOption(option);
});```

### Current Behavior

The chart does not render any colours on the map (not even the basic colour for elements with no data)

### Expected Behavior

States with categories (in the above case: Alabama, Alaska, Texas) should be coloured on the map into their corresponding piecewise categories of 'Apples', 'Oranges', 'Pears'.

### Environment

```markdown
Latest Chrome and Edge

Any additional comments?

No response