Made repository methods asynchronous. Simplified playlist repository. Use playlist manager in the app, and left playlist repository to only be used by the playlist manager.

Harmonia.WinUI/App.xaml.cs

@@ -1,4 +1,5 @@
 using Harmonia.Core.Extensions;
+using Harmonia.Core.Playlists;
 using Harmonia.WinUI.Caching;
 using Harmonia.WinUI.Storage;
 using Harmonia.WinUI.ViewModels;
@@ -38,8 +39,10 @@ public partial class App : Application
         InitializeComponent();
     }
 
-    protected override void OnLaunched(LaunchActivatedEventArgs args)
+    protected override async void OnLaunched(LaunchActivatedEventArgs args)
     {
+        await ServiceProvider.InitializeHarmoniaAsync();
+
         _mainWindow = ServiceProvider.GetRequiredService<MainWindow>();
         _mainWindow.Activate();
     }