Avalonia: Another Cleanup (#3494)

* Avalonia: Another Cleanup

This PR is a cleanup to the avalonia code recently added:

- Some XAML file are autoformatted like a previous PR.
- Dlc is renamed to DownloadableContent (Locale exclude).
- DownloadableContentManagerWindow is a bit improved (Fixes #3491).
- Some nits here and there.

* Fix GTK

* Remove AttachDebugDevTools

* Fix last warning

* Fix JSON fields

Ryujinx.Ava/Ui/Models/DownloadableContentModel.cs

@@ -0,0 +1,18 @@
+namespace Ryujinx.Ava.Ui.Models
+{
+    public class DownloadableContentModel
+    {
+        public bool   Enabled       { get; set; }
+        public string TitleId       { get; }
+        public string ContainerPath { get; }
+        public string FullPath      { get; }
+
+        public DownloadableContentModel(string titleId, string containerPath, string fullPath, bool enabled)
+        {
+            TitleId       = titleId;
+            ContainerPath = containerPath;
+            FullPath      = fullPath;
+            Enabled       = enabled;
+        }
+    }
+}