Change CSS font-family by language preference

Fixes https://github.com/jellyfin/jellyfin-web/issues/913.

- Update `lang` attribute of `html` element on user preference change.
- Choose appropriate `font-family` depending on `lang` attribute using
  attribute selectors in CSS.
- Add `Noto Sans TC`, the Traditional Chinese (Taiwan variant).
- Fix event listener registration in `globalize.js`.

src/scripts/globalize.js

@@ -1,7 +1,7 @@
 import { Events } from 'jellyfin-apiclient';
 import isEmpty from 'lodash-es/isEmpty';
 
-import * as userSettings from './settings/userSettings';
+import { currentSettings as userSettings } from './settings/userSettings';
 
 /* eslint-disable indent */
 

src/scripts/site.js

@@ -274,11 +274,24 @@ async function onAppReady() {
             }
         };
 
-        Events.on(ServerConnections, 'localusersignedin', handleStyleChange);
-        Events.on(ServerConnections, 'localusersignedout', handleStyleChange);
+        const handleLanguageChange = () => {
+            const locale = globalize.getCurrentLocale();
+
+            document.documentElement.setAttribute('lang', locale);
+        };
+
+        const handleUserChange = () => {
+            handleStyleChange();
+            handleLanguageChange();
+        };
+
+        Events.on(ServerConnections, 'localusersignedin', handleUserChange);
+        Events.on(ServerConnections, 'localusersignedout', handleUserChange);
         Events.on(currentSettings, 'change', (e, prop) => {
             if (prop == 'disableCustomCss' || prop == 'customCss') {
                 handleStyleChange();
+            } else if (prop == 'language') {
+                handleLanguageChange();
             }
         });