Implement feature flags and update views

This commit implements feature flags using the "ylsideas/feature-flags" library and updates various frontend views to show or hide sections based on the feature flag. Additionally, a new migration file is created for the features database table and the LibraryItem model is updated with a new searchLibraryItems function. The composer.json and composer.lock files are updated to include the new dependencies.

resources/views/livewire/book-case/world-map.blade.php

@@ -54,6 +54,7 @@
     {{-- FOOTER --}}
     <livewire:frontend.footer/>
 
+    @feature('nostr.groups')
     <div wire:ignore class="z-50 hidden md:block">
         <script
             src="{{ asset('dist/einundzwanzig.chat.js') }}"
@@ -64,4 +65,6 @@
         ></script>
         <link rel="stylesheet" href="{{ asset('dist/einundzwanzig.chat.css') }}">
     </div>
+    @endfeature
+
 </div>