feat: add localisation

lib/app/app.dart

@@ -5,6 +5,7 @@ import 'package:provider/provider.dart';
 import '../models/settings.dart';
 import '../viewmodels/settings_view_model.dart';
 import '../theme.dart';
+import '../l10n/app_localizations.dart';
 
 class KoolTabApp extends StatefulWidget {
   const KoolTabApp({super.key, required this.router});
@@ -30,9 +31,12 @@ class _KoolTabAppState extends State<KoolTabApp> {
     final settings = context.watch<SettingsViewModel>().settings;
 
     return MaterialApp.router(
-      title: 'KoolTab',
+      onGenerateTitle: (context) => AppLocalizations.of(context).appTitle,
       debugShowCheckedModeBanner: false,
       routerConfig: widget.router,
+      locale: _localeFor(settings.language),
+      localizationsDelegates: AppLocalizations.localizationsDelegates,
+      supportedLocales: AppLocalizations.supportedLocales,
       theme: lightTheme,
       darkTheme: _themeFor(settings.themeMode),
       themeMode: _mapThemeMode(settings.themeMode, context),
@@ -46,16 +50,22 @@ class _KoolTabAppState extends State<KoolTabApp> {
       AppThemeMode.dark => ThemeMode.dark,
       AppThemeMode.light => ThemeMode.light,
       AppThemeMode.ugly => ThemeMode.dark,
-      AppThemeMode.system =>
-        hasLoaded ? ThemeMode.system : ThemeMode.dark,
+      AppThemeMode.system => hasLoaded ? ThemeMode.system : ThemeMode.dark,
     };
   }
 
-
   ThemeData _themeFor(AppThemeMode mode) {
     return switch (mode) {
       AppThemeMode.ugly => uglyTheme,
       _ => darkTheme,
     };
   }
-}
+
+  Locale? _localeFor(AppLanguage language) {
+    return switch (language) {
+      AppLanguage.system => null,
+      AppLanguage.english => const Locale('en'),
+      AppLanguage.dutch => const Locale('nl'),
+    };
+  }
+}