[Config] refactoring for code readability

[designe]

Motivation

Refactoring for code readability in config

Have you read the Contributing Guidelines on pull requests?

YES

Test Plan

rustfmt and
unit test is passed on config

Related PRs

N/A

[huitseeker]

Thanks!

We currently run rustfmt with reorder_imports but are not strict on ordering between lines/groups at the moment. If we decided to do so, a tool-based approach that would maintain the ordering of imports would be more sustainable than a one-off, and required for a repository of this size.

We'll be tracking rustfmt evolutions on the issue, thanks for raising attention on this.