Unify defining number formats for different locales

[MickL]

Clear and concise description of the problem

At the moment number formats need to be defined for every locale, but this results in duplicate code:

numberFormats: {
    de: {
      currency: {
        style: 'currency',
        currency: 'EUR',
      },
    },
    fr: {
      currency: {
        style: 'currency',
        currency: 'EUR',
      },
    },
    es: {
      currency: {
        style: 'currency',
        currency: 'EUR',
      },
    },
  },
  datetimeFormats: {
    de: {
      date: {
        year: 'numeric',
        month: '2-digit',
        day: '2-digit',
      },
    },
    fr: {
      date: {
        year: 'numeric',
        month: '2-digit',
        day: '2-digit',
      },
    },
    es: {
      date: {
        year: 'numeric',
        month: '2-digit',
        day: '2-digit',
      },
    },
  },

This is a simple example but imagine having 27 EU countries and defining multiple date formats and all of them are the same.

Suggested solution

Maybe something like this:

numberFormats: {
    currency: {
      style: 'currency',
      currency: 'EUR',
      locales: ['de', 'fr', 'es'],
    },
  },
  datetimeFormats: {
    date: {
      year: 'numeric',
      month: '2-digit',
      day: '2-digit',
      locales: ['de', 'fr', 'es'],
    },
  },

Additionally locales could be optional: If not defined it applies to all locales.

Alternative

No response

Additional context

No response

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