`string`: Respect width parameter in formatters.

[github-actions[bot]]

On 2022-05-28 @recmo wrote in 1ec2e50 “Recognize new tags”:

Respect width parameter in formatters.

    Binary, Debug, Display, Formatter, LowerHex, Octal, Result as FmtResult, UpperHex,
};
use std::str::FromStr;
use thiserror::Error;

// FEATURE: Respect width parameter in formatters.

impl<const BITS: usize, const LIMBS: usize> Display for Uint<BITS, LIMBS> {
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
        // Base convert 19 digits at a time
        const BASE: u64 = 10_000_000_000_000_000_000_u64;

From src/string.rs:8