refactor(formatter): improve string normalization

[Conaclos]

Summary

While I was working on #3558, I noted a room for improving string utilities.

This PR improves the implementation of the string utilities:

• Reduce an unnecessary lookup (counting the number of characters) when we check the number of quotes inside a string
• Avoid a string allocation when string contents are normalized
• Avoid a string allocation when quotes are normalized

The PR has also the aim of improving performance of string normalization by avoiding peekable() and iterating over bytes instead of chars.

The PR also normalizes strings before evaluating if quotes are needed for import attribute keys.
This is a follow-up of #3558.

There is more room for improvements for example to avoid code duplication.
The change are already large in this PR, I prefer to defer them in a follow-up PR.

Test Plan

I improved the test coverage of the normalise_string function.

[codspeed-hq]

CodSpeed Performance Report

Merging #3564 will not alter performance

_{Comparing conaclos/string-utils-refactor (7b073c9) with main (3229b32)}

Summary

✅ 103 untouched benchmarks

⁉️ 1 dropped benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	conaclos/string-utils-refactor	Change
⁉️	js_formatter[ios.d_11036528575252089605.d.ts]	778.8 ms	N/A	N/A