i18n: Enabling Vietnamese

frontend/angular.json

@@ -87,6 +87,10 @@
             "translation": "src/locale/messages.fi.xlf",
             "baseHref": "/fi/"
           },
+          "vi": {
+            "translation": "src/locale/messages.vi.xlf",
+            "baseHref": "/vi/"
+          },
           "zh": {
             "translation": "src/locale/messages.zh.xlf",
             "baseHref": "/zh/"

frontend/src/app/app.constants.ts

@@ -111,6 +111,6 @@ export const languages: Language[] = [
 // { code: 'th', name: 'ไทย' },             // Thai
    { code: 'tr', name: 'Türkçe' },          // Turkish
    { code: 'uk', name: 'Українська' },      // Ukrainian
-// { code: 'vi', name: 'Tiếng Việt' },      // Vietnamese
+   { code: 'vi', name: 'Tiếng Việt' },      // Vietnamese
    { code: 'zh', name: '中文' },            // Chinese
 ];