misc: chore: Move the windows that are shown via ContentDialogs out of Ryujinx.Ava.UI.Windows (they're not windows)

src/Ryujinx/UI/Views/Dialog/DlcSelectView.axaml.cs

@@ -0,0 +1,40 @@
+using Avalonia.Controls;
+using Avalonia.Styling;
+using FluentAvalonia.UI.Controls;
+using Ryujinx.Ava.Common.Locale;
+using Ryujinx.Ava.Common.Models;
+using Ryujinx.Ava.UI.Controls;
+using Ryujinx.Ava.UI.Helpers;
+using Ryujinx.Ava.UI.ViewModels;
+using Ryujinx.Ava.Systems.AppLibrary;
+using System.Threading.Tasks;
+
+namespace Ryujinx.Ava.UI.Views.Dialog
+{
+    public partial class DlcSelectView : RyujinxControl<DlcSelectViewModel>
+    {
+        public DlcSelectView()
+        {
+            InitializeComponent();
+        }
+
+#nullable enable
+        public static async Task<DownloadableContentModel?> Show(ulong selectedTitleId, ApplicationLibrary appLibrary)
+#nullable disable
+        {
+            DlcSelectViewModel viewModel = new(selectedTitleId, appLibrary);
+
+            ContentDialog contentDialog = new()
+            {
+                PrimaryButtonText = LocaleManager.Instance[LocaleKeys.Continue],
+                SecondaryButtonText = string.Empty,
+                CloseButtonText = string.Empty,
+                Content = new DlcSelectView { ViewModel = viewModel }
+            };
+
+            await ContentDialogHelper.ShowAsync(contentDialog.ApplyStyles());
+
+            return viewModel.SelectedDlc;
+        }
+    }
+}