Custom register fields: Implement translation for Country and US State lists

[mirovladimitrovski]

Description

Country and US State lists have previously been implemented as static lists of country/state names in English.

Steps completed:

According to our definition of done, I have completed the following steps:

• Acceptance criteria met
• Unit tests added
• Docs updated (including config and env variables)
• Translations added
• UX tested
• Browsers / platforms tested
• Rebased & ready to merge without conflicts
• Reviewed own code

[github-actions]

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[dbudzins]

Did you just add the translations directly from English? This is something that is relatively easily searchable:

https://www.language-pro.info/names-of-the-u-s-states-in-spanish/
https://www.blablalang.com/countries-nationalities-spanish/

Or just leave them blank so we know they need to be properly filled in.