Narrow typed locale identifiers

[warflash]

Describe the feature

const { locale, locales } = useI18n()

Currently locale is typed as string and locales is string[]. The suggestion is to use tighter types like locale -> "en" | "de" in the case of a config like:

    i18n: {
        locales: [
            { code: "en", iso: "en-US", file: "en.json" },
            { code: "de", iso: "de-DE", file: "de.json" },
        ],
    },

That would make type safe access to typed records possible. e.g.

const MIN_SEARCH_LEN_BY_LOCALE = {
    en: 3,
    de: 3,
    ko: 1,
}

const { locale, locales } = useI18n()

const minLen = MIN_SEARCH_LEN_BY_LOCALE[locale] 

Additional information

• [ ] Would you be willing to help implement this feature?
• [ ] Could this feature be implemented as a module?

Final checks

• [X] Read the contribution guide (The contribution guideline of nuxt-modules/i18n is compliant with Nuxt too).
• [X] Check existing discussions and issues.

[BobbieGoede]

Should be resolved by #3025, which will be included in v9

[warflash]

Thanks! 💚