misc: chore: [ci skip] small Avalonia project restructure

Moved the Views that existed in the Controls namespace into the Ryujinx.Ava.UI.Views.Misc namespace
Moved UpdateWaitWindow to Ryujinx.Ava.UI.Windows

src/Ryujinx/UI/Windows/UpdateWaitWindow.axaml.cs

@@ -0,0 +1,30 @@
+using Avalonia.Controls;
+using System.Threading;
+
+namespace Ryujinx.Ava.UI.Windows
+{
+    public partial class UpdateWaitWindow : StyleableWindow
+    {
+        public UpdateWaitWindow(string primaryText, string secondaryText, CancellationTokenSource cancellationToken) : this(primaryText, secondaryText)
+        {
+            SystemDecorations = SystemDecorations.Full;
+            ShowInTaskbar = true;
+
+            Closing += (_, _) => cancellationToken.Cancel();
+        }
+
+        public UpdateWaitWindow(string primaryText, string secondaryText) : this()
+        {
+            PrimaryText.Text = primaryText;
+            SecondaryText.Text = secondaryText;
+            WindowStartupLocation = WindowStartupLocation.CenterOwner;
+            SystemDecorations = SystemDecorations.BorderOnly;
+            ShowInTaskbar = false;
+        }
+
+        public UpdateWaitWindow()
+        {
+            InitializeComponent();
+        }
+    }
+}