Format 'use declaration' in a more readable way

[kaiwk]

📋 Description

See: https://users.rust-lang.org/t/use-declaration-convention/45251

I'm not sure if rustfmt has option to group the use statements, i think that would make it more readable. For now, if one forget add a blank line between use std::... and use crate::..., rustfmt will sort them by ASCII I suppose.

Besides, rust-analyzer auto import will add use statements in std > third-party > current crate order, with blank lines among them.

[kaiwk]

Looks like there's a PR(#4445) for it.