🤔列头格式自动转为文本

### 🖋 Description
pivotsheet下s2DataConfig内columns传入的字段好像强制会转为string，导致meta内的formatter错误
应用场景：column为int型的timestamp，通过timeformatter来格式化value
### 😊 Expected Behavior
保持字段的类型不变，通过formatter来控制更合理？
### 😅 Current Behavior
数值被转成string，现在formatter函数为了兼容，将string转回数值，再进行格式化

Start at the pivotsheet s2DataConfig entry point, focusing on how the columns field reaches meta and its formatter. Reproduce the issue with an integer timestamp column and a time formatter. Done means the column value retains its original type and the formatter can format it without converting a string back to a number.

Written by the indexing model from the issue text.