Add: Japanese, Afrikaans, Filipino, Thai and Vietnamese

## Issue
Closes 5646: Add more completed language translations

## Notes
SDK uses RFC 5646 format, which led me to
https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry. Took the codes from here. They match what's already used in Transifex, so that's good.

ui/constants/languages.js

@@ -43,6 +43,7 @@ const LANGUAGES = {
   fa: ['Persian', 'فارسی'],
   ff: ['Peul', 'Fulfulde'],
   fi: ['Finnish', 'Suomi'],
+  fil: ['Filipino', 'Wikang Filipino'],
   fj: ['Fijian', 'Na Vosa Vakaviti'],
   fo: ['Faroese', 'Føroyskt'],
   fr: ['French', 'Français'],

ui/constants/supported_languages.js

@@ -1,6 +1,7 @@
 import LANGUAGES from './languages';
 
 const SUPPORTED_LANGUAGES = {
+  af: LANGUAGES.af[1],
   en: LANGUAGES.en[1],
   da: LANGUAGES.da[1],
   'zh-Hans': LANGUAGES['zh-Hans'][1],
@@ -9,11 +10,13 @@ const SUPPORTED_LANGUAGES = {
   nl: LANGUAGES.nl[1],
   no: LANGUAGES.no[1],
   fi: LANGUAGES.fi[1],
+  fil: LANGUAGES.fil[1],
   fr: LANGUAGES.fr[1],
   de: LANGUAGES.de[1],
   gu: LANGUAGES.gu[1],
   hi: LANGUAGES.hi[1],
   id: LANGUAGES.id[1],
+  ja: LANGUAGES.ja[1],
   jv: LANGUAGES.jv[1],
   it: LANGUAGES.it[1],
   ms: LANGUAGES.ms[1],
@@ -26,6 +29,7 @@ const SUPPORTED_LANGUAGES = {
   ru: LANGUAGES.ru[1],
   sr: LANGUAGES.sr[1],
   sk: LANGUAGES.sk[1],
+  th: LANGUAGES.th[1],
   ur: LANGUAGES.ur[1],
   ca: LANGUAGES.ca[1],
   es: LANGUAGES.es[1],
@@ -34,6 +38,7 @@ const SUPPORTED_LANGUAGES = {
   cs: LANGUAGES.cs[1],
   kn: LANGUAGES.kn[1],
   uk: LANGUAGES.uk[1],
+  vi: LANGUAGES.vi[1],
 };
 
 // Properties: language code (e.g. 'ja')