[Feature Request] el-table-column的prop属性能否支持数组类型？Can the prop attribute of el-table-column support array type?

### Existing Component
是

### Component Name
el-table-column

### Description
在某些动态情况下，`prop`属性也是动态的，例如3月份每日的金额prop如果是`3-1.amount`则正常取值，如果prop是`3.1.amount`却可能造成取值错误，而支持`['3.1','amount']`格式的prop就可以解决，在Element Plus中也一样。
In some dynamic situations, the `prop` attribute is also dynamic. For example, if the daily amount prop in March is `3-1.amount`, the value will be normal. If the prop is `3.1.amount`, it may cause the value to change. The error can be solved by supporting prop in the `['3.1','amount']` format, and the same is true in Element Plus.