Intl improvement: Locale, getCanonicalLocales, supportedLocalesOf

[duonglaiquang]

This PR does the following

• Refactor Intl initialization — Move logic from JavaScriptEngine into Intl.init(), making the Intl module self-contained and enabling static function registration (for getCanonicalLocales() in the later commit)

• Implement Intl.Locale

• Implement Intl.getCanonicalLocales()

• Add supportedLocalesOf() to Intl.NumberFormat and Intl.DateTimeFormat

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[rbri]

@duonglaiquang this looks great, looking forward to the things you like to do on top of this.

[rbri]

@duonglaiquang looks like my latest cleanup has borken something, working on that

[rbri]

@duonglaiquang have fixed the toString stuff and switched to array-like support. this is a bit closer to the spec. Maybe you like to backport that to your branch