Webatrice: i18n (#4562)

* implement i18n capability

* reset package.lock file

* remove custom fallback

* fix relative path for i18n files

* check for language support before fetch request

* add LanguageDropdown component, es translation file to prove functionality

* remove boilerplate

* bundle default english translation with app

* add missing file

* rollup component-level i18n files

* cleanup

Co-authored-by: Jeremy Letto <jeremy.letto@datasite.com>

webclient/src/i18n.ts

@@ -0,0 +1,30 @@
+import i18n from 'i18next';
+import LanguageDetector from 'i18next-browser-languagedetector';
+import { initReactI18next } from 'react-i18next';
+
+import { Language } from 'types';
+
+import I18nBackend from './i18n-backend';
+
+// Bundle default translation with application
+import translation from './i18n-default.json';
+
+i18n
+  .use(I18nBackend)
+  .use(LanguageDetector)
+  .use(initReactI18next)
+  // for all options read: https://www.i18next.com/overview/configuration-options
+  .init({
+    fallbackLng: Language['en-US'],
+    resources: {
+      [Language['en-US']]: { translation },
+    },
+    partialBundledLanguages: true,
+
+    interpolation: {
+      // not needed for react as it escapes by default
+      escapeValue: false,
+    },
+  });
+
+export default i18n;