Fix application list loads slowly when RyuLDN is enabled

Currently, application list will not show until ApplicationLibrary_LdnGameDataReceived calls ViewModel.RefreshView();, forcing a refresh. This makes application list load slowly when RyuLDN is enabled.

src/Ryujinx/UI/ViewModels/MainWindowViewModel.cs

@@ -172,7 +172,8 @@ namespace Ryujinx.Ava.UI.ViewModels
             Applications.ToObservableChangeSet()
                 .Filter(Filter)
                 .Sort(GetComparer())
-                .Bind(out _appsObservableList).AsObservableList();
+                .Bind(out _appsObservableList)
+                .Subscribe();
 
             _rendererWaitEvent = new AutoResetEvent(false);