feat: Add Korean language support

Add Korean translation file (kr/translation.json)
Update i18n.js to include 'kr' in whitelist
Add Korean option to SelectLanguage component

Manual inspection of full translation.
TODO: check full-text about result of word translation

apps/OpenSign/src/components/pdf/SelectLanguage.jsx

@@ -10,7 +10,8 @@ function SelectLanguage(props) {
     { value: "fr", text: "Français" }, //french
     { value: "it", text: "Italiano" }, //italian
     { value: "de", text: "Deutsch" }, //german
-    { value: "hi", text: "हिन्दी" } //hindi
+    { value: "hi", text: "हिन्दी" }, //hindi
+    { value: "kr", text: "한국어" } //korean
   ];
   const defaultLanguage = i18next.language || "en";
   const [lang, setLang] = useState(defaultLanguage);

apps/OpenSign/src/i18n.js

@@ -25,7 +25,7 @@ i18n
     interpolation: {
       escapeValue: false // Not needed for react as it escapes by default
     },
-    whitelist: ["en", "es", "fr", "it", "de", "hi"] // List of allowed languages
+    whitelist: ["en", "es", "fr", "it", "de", "hi", "kr"] // List of allowed languages
   });
 
 export default i18n;