Incubator-echarts: [需求] toolbox的dataZoom开关设置默认打开

[GFwer]

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Issue Details

现在如果想使用toolbox中的dataZoom功能需要先点击才能够触发，是否能像highcharts一样一开始就默认打开或者提取出来可供配置？

而且我觉得“恢复缩放”这个按钮应该在有经过缩放之后才展示出来。

Expected Behavior

有一个toolbox.feature.dataZoom.active的配置项配置默认是否激活该功能

Current Behavior

需要点击图标之后才能激活功能

Online Example

Topics

Anything Else We Need to Know

Environment

• ECharts version；ECharts 版本: {DESCRIBE_HERE} 4.2.0rc2

• [ ] It happens only on certain browsers or operating systems. 对于特定浏览器或操作系统才会出现的问题，请提供相应环境信息：{BROWSER_VERSION_OR_OS_INFORMATION_HERE}

[100pah]

// Activate the datazoom brush.
myChart.dispatchAction({
    type: 'takeGlobalCursor',
    key: 'dataZoomSelect',
    dataZoomSelectActive: true // activate or inactivate
});

[GFwer]

好的，感谢！（我再搜就能发现了...