使用transform aggregate的 sum 累加时候，小数点存在精度丢失问题

`
const dv = new DataSet().createView().source([
{
item: '2019',
columnValue: 1.01,
type: 'a'
},
{
item: '2019',
columnValue: 2.01,
type: 'a'
},
{
item: '2020',
columnValue: 1.01,
type: 'a'
},
{
item: '2020',
columnValue: 2.22,
type: 'a'
},
])
dv.transform({
type: 'aggregate', // 别名summary
fields: ['columnValue'], // 统计字段集
operations: ['sum'], // 统计操作集
as: ['value'], // 存储字段集
groupBy: ['item', 'type'], // 分组字段集
})

console.log('dv', dv.rows)
`
#### 输出结果

#### 原因
sum 使用的第三方库 simple-statistics 里面并没有处理浮点计算精度丢失问题

希望能修复这个问题，感谢

Start at the aggregate transform using the provided DataSet example, then inspect how its sum operation delegates to the mentioned simple-statistics dependency. Reproduce the grouped decimal calculation and verify that the resulting values no longer show floating-point precision loss.

Written by the indexing model from the issue text.