feat(theme): find best locale match to format last update

[userquin]

Description

This PR includes the logic to find the best locale match from navigator.languages including:

• iso-639 support for Latin America: es-419
• Edge browser case for ca-valencia lang (Spanish co-official: Valencià)
• the new logic will be applied only when not enabling forceLocale (per locale) and will return undefined (current logic) if not found
• add time lang attribute logic
• use browser/OS language via Intl.DateTimeFormat().resolvedOptions().locale when best match not found

When testing this PR with Spanish, you should change replace lang: 'es-CO', with lang: 'es', (using medium for time style, that's why we have the seconds in the screenshots below) in the es.ts module.

You can add the languages to your browser sorting them (at least on Chrome).

NOTE about using browser/OS default language:

• using english page the text in english => no time lang attr (en, en-GB, en-US should be present in languages)
• accessing spanish page with es-ES=> time lang with es-ES with proper format HH24 (es-ES should be be present inlanguages)
• moving es-ES after es-AR => time lang with es-AR with proper format AM/PM (es-ES should be present in languages)
• other VP lang (pt, jp...) => using default browser/OS language, in my case es-ES => time lang with es-ES with proper format HH24 (doesn't matter if I put es-AR before es-ES)

Linked Issues

Additional Context

Testing Intl.DateTimeFormat script

[new Date()].forEach((d) => {
  const acc = {}

  Array.from(['es', 'es-419', 'es-ES', 'es-AR', 'es-CO', 'es-VE', 'es-MX', 'pt-PT', 'pt-BR']).forEach((l) => {
    const format = new Intl.DateTimeFormat(l, {
    dateStyle: 'short', timeStyle: 'short'
  }).format
    acc[l] = {
      date: d,
      format: format(d),
    }
  })
  console.table(acc)
})

Spanish translation with es-AR

Spanish translation with es-ES

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Tip

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[userquin]

use lang attr via ref value here instead element ref

[bluwy]

Is this still needed with #4935 merged?