Realms settings-related i18n key(s) / translation string missing from all .lang files

I was trying to help someone else and apparently they got an error message that was missing a translation string for it.

After I investigated my vanilla-installed copy, no such translation string existed in any of the resource packs for any language.

`realmsSettingsScreen.manageSubscriptionNotAvailable.body` is the only key that is not obscured or truncated in their screenshot (I'll inform them about 3rd-party app stuff).

If the case is a legit missing translation key, the attached CSV file should be easily able to help find what pack has at least one `.lang` file with a specific key. (feel free to unmark as private and / or remove the CSV file as required by rules)