fix(css_formatter): keep @charset double quote in single quote config

[fireairforce]

Summary

closes: #4384

@charset must always have double quotes: https://www.w3.org/TR/css-syntax-3/#determine-the-fallback-encoding

I add a param StringLiteralParentKind for impl FormatLiteralStringToken to judge if the CSS String's parent is a CSS_CHARSET_AT_RULE which represents the syntax like:@charset, i refer the same util at biome_js_formatter.

if the string is StringLiteralParentKind::CharsetAtRule, i will use the double quote for the string in any case, or we will execute the normal logic of biome_css_formatter.

Test Plan

Test case as follows:

@charset·"UTF-8";
@charset "iso-8859-15";
@charset "any-string-is-okay";

[codspeed-hq]

CodSpeed Performance Report

Merging #4404 will not alter performance

_{Comparing fireairforce:fix-4384 (97e64a8) with main (3530f2f)}

Summary

✅ 99 untouched benchmarks

[fireairforce]

@ematipico here is my changelog, lol