🐛[BUG]pro components 3.1.11 valueType为percent时，precision失效

在pro components 3.1.11这个版本中。很可能之前的版本也是。

在protable中，如果columns是这样写的。

valueType: () => ({ type: 'percent', rate: 2, precision: 8 })

那么，小数被显示出来的时候，永远是2位，永远不会是8位。

如果你有一个值，是0.000001，那么显示出来的一直是0.00%

Start at the ProTable column configuration and the percent valueType renderer, focusing on how rate and precision are applied when displaying decimal values. Reproduce the reported configuration with a value such as 0.000001; done means precision: 8 controls the displayed percentage rather than always showing two decimal places.

Written by the indexing model from the issue text.