[Bug] Legend do not break in VisualMap piecewise option

### Version

5.3.3

### Link to Minimal Reproduction

https://echarts.apache.org/examples/en/editor.html?c=calendar-heatmap

### Steps to Reproduce

Hi,
I was trying to use VisualMap with piecewise option, however, not all the legends are visible, see the image below:

Is it possible to auto break the legend, or manually define the number of columns?

### Current Behavior

The VisualMap legend does not fit into the screen.

### Expected Behavior

Automatically break the legend if doesn't fit.

### Environment

```markdown
- OS:Android
- Browser: Chrome
- Framework:
```

### Any additional comments?

_No response_