Add countries in Japanese

[lawriecate]

Issue#

No-Story

I'm working on a system based in Japan and we want to have test countries data in both English and Japanese!

I have tried to check this follows contribution guidelines but this is my first time so please let me know if I missed anything 🙏

Description:

• Adds data for countries in Japanese locale
• Sourced from https://ja.wikipedia.org/wiki/%E5%9B%BD%E3%81%AE%E4%BA%BA%E5%8F%A3%E9%A0%86%E3%83%AA%E3%82%B9%E3%83%88 (with exception of adding Taiwan following list of countries in EN locale)

[youpong]

Duplicated item "本土と属領" appears 6 times in your change.

[lawriecate]

Duplicated item "本土と属領" appears 6 times in your change.

Ah thank you for catching that, I have removed it now !

[psibi]

Thank you both!