feat(settings): add appearance settings with dark mode toggle and translations

- Introduced new appearance settings page with a dark mode toggle feature.
- Added localization support for English, Spanish, and Portuguese in appearance settings.
- Removed the ThemeSelector component and updated PreferenceSelector accordingly.

worklenz-frontend/src/lib/settings/settings-constants.ts

@@ -11,6 +11,7 @@ import {
   TeamOutlined,
   UserOutlined,
   UserSwitchOutlined,
+  BulbOutlined,
 } from '@ant-design/icons';
 import React, { ReactNode } from 'react';
 import ProfileSettings from '../../pages/settings/profile/profile-settings';
@@ -25,6 +26,7 @@ import TeamMembersSettings from '@/pages/settings/team-members/team-members-sett
 import TeamsSettings from '../../pages/settings/teams/teams-settings';
 import ChangePassword from '@/pages/settings/change-password/change-password';
 import LanguageAndRegionSettings from '@/pages/settings/language-and-region/language-and-region-settings';
+import AppearanceSettings from '@/pages/settings/appearance/appearance-settings';
 
 // type of menu item in settings sidebar
 type SettingMenuItems = {
@@ -52,6 +54,13 @@ export const settingsItems: SettingMenuItems[] = [
     icon: React.createElement(NotificationOutlined),
     element: React.createElement(NotificationsSettings),
   },
+  {
+    key: 'appearance',
+    name: 'appearance',
+    endpoint: 'appearance',
+    icon: React.createElement(BulbOutlined),
+    element: React.createElement(AppearanceSettings),
+  },
   {
     key: 'change-password',
     name: 'change-password',