* Adds localization manifests for region-specific cultures
This is to support backwards-compatibility and v13 upgradability.
* Removed `uiCulture` from Vietnamese localizations
since it duplicated the English fallback texts.
* 'en' localization file formatting
* Update src/Umbraco.Web.UI.Client/src/assets/lang/en.ts
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>