support parse number with high precision as possible in sonic ast

[liuq19]

Support parse number with high precision as possible.

For example:

1. If number is negative integer, parse number into int64,
2. If number is positive integer, parse number into uint64,
3. Others, parse number into float64.

Now usenumber only cast number to json.Number, it is string type. Also, ast not have UseInt64 API. So we can provide a new API, to do it.

[chenlinli]

Will the new API be supported？

[AsterDY]

sonic.UseInt64.UnmarshalString(node.Raw(), map{}) can work around for first-touched node (not trigger node.Get()|Set() yet)

[chenlinli]

这是来自QQ邮箱的假期自动回复 谢谢，您的邮件我已收到。