Add missing languages and correct translations of languages.

[IDisposable]

Summary

• When languages are added to the localization options, we need to always add them to each language. This was not done when Japanese and Portuguese were added so we didn't have a self-localized display string for those in the English locale.
• When languages are added to the localization options, we need to add all other languages in the language of the new localization. For all locale*.json_ files, this means the translation of a "locale_*": should be in the language OF the containing locale file. For example, in the locale_pt.json, we should have "locale_en": "Inglês". This is different from the locale_en.json which always shows the name in the native language of the locale being represented, e.g. "locale_es": "Español", is the Spanish way of saying spanish.

Changes

• Add missing locale_jp and locale_pt to all the existing languages (were missed when those PRs were merged)
  • In the en.json added them in their own native language
  • In the rest added them in the native language of the containing file
• Corrected the locale translations in ja.json to be in Japanese (e.g. "locale_en": "英語", for English)
• Corrected the locale translations in zh-tw.json to be in Traditional Chinese (e.g. "locale_es": "西班牙語", for Spanish)
• Correct the Chinese locale option translations in all the other ui/localization/messages/ files as they should be in the native language of the containing file (e.g, "locale_zh": "Kinesisk (forenklet)", for the Danish translation of Chinese)
• Resorted translations using npm run i18n:resort for diff-stability later
• Updated documentation of the process of adding localizations to spell out the need to resort, and how to correctly create a new localization target.
• Added utility function getLocalizedMessage that allows dynamic access to the localized strings and updated the map_locale_code_to_name to use it so we don't need to also update the previous switch statement.

Checklist

• Ran make test_e2e locally and passed
• Linked to issue(s) above by issue number (e.g. Closes #<issue-number>)
• One problem per PR (no unrelated changes)
• Lints pass; CI green

[IDisposable]

The design spelled out here are intended to ensure that when the UI is in English (the default), we show each language in their native language and when the UI is in any other language we show the languages in both the current language and in their native language.

Thus the language selector to looks like this in German:

(notice in 0.5.2 that the Chinese is incorrectly displaying only Chinese... this is because the line in the de.json for "locale_zh"was not entered in Chinese, not as a German phrase.)

...and this for for English (the default language)

[adamshiervani]

Looks good to me. Just one small docs change.

[IDisposable]

Here's the results of the changes

[adamshiervani]

Just need that Japanese bokmål fix and then we'r good to go! Great catch

[IDisposable]

Just need that Japanese bokmål fix and then we'r good to go! Great catch

Updated and pushed.