Tracking `rustfmt` unstable options

[mattheworris]

This is a tracking issue for rustfmt features that should be stabilized. Frequency.xyz currently uses these features and therefore requires a nightly version. When these options are stabilized, we can remove our dependence on nightly.

• [ ] https://github.com/rust-lang/rustfmt/issues/4991
  • grouping of use statements: current option Crate
• [ ] https://github.com/rust-lang/rustfmt/issues/3363
  • type, const first, then macros and methods: current option: false,
• [ ] https://github.com/rust-lang/rustfmt/issues/3367
  • spaces around the .., ..=, and ... range operators: current option false
• [ ] https://github.com/rust-lang/rustfmt/issues/3368
  • where to put binary operator on mulitline: current option Back
• [ ] https://github.com/rust-lang/rustfmt/issues/3373
  • whether arm bodies are wrapped: current option: false
• [ ] https://github.com/rust-lang/rustfmt/issues/3378
  • semicolon after break, continue and reture: current option false
• [ ] https://github.com/rust-lang/rustfmt/issues/3379
  • trailing comma for lists: current option Vertical