支持树形结构的导出

[lalala8462]

目前业务系统中需要导出树形结构的数据,目前看esayexcel中不支持设置 groupRow
所以新增了一个 WriteTreeData 类 支持定义父子级关系数据
在 com.alibaba.excel.write.executor.ExcelWriteAddExecutor#add 中判断数据类型
当为 WriteTreeData 时递归遍历子数据集 然后 sheet.groupRow

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[opcooc]

这个可以啊 有些导出确实是树层级的 good good