infra: Make Avalonia the default UI (#6375)

* misc: Move Ryujinx project to Ryujinx.Gtk3

This breaks release CI for now but that's fine.

Signed-off-by: Mary Guillemard <mary@mary.zone>

* misc: Move Ryujinx.Ava project to Ryujinx

This breaks CI for now, but it's fine.

Signed-off-by: Mary Guillemard <mary@mary.zone>

* infra: Make Avalonia the default UI

Should fix CI after the previous changes.

GTK3 isn't build by the release job anymore, only by PR CI.

This also ensure that the test-ava update package is still generated to
allow update from the old testing channel.

Signed-off-by: Mary Guillemard <mary@mary.zone>

* Fix missing copy in create_app_bundle.sh

Signed-off-by: Mary Guillemard <mary@mary.zone>

* Fix syntax error

Signed-off-by: Mary Guillemard <mary@mary.zone>

---------

Signed-off-by: Mary Guillemard <mary@mary.zone>

src/Ryujinx/UI/Renderer/EmbeddedWindowOpenGL.cs

@@ -0,0 +1,94 @@
+using OpenTK.Graphics.OpenGL;
+using Ryujinx.Common.Configuration;
+using Ryujinx.Common.Logging;
+using Ryujinx.Graphics.GAL;
+using Ryujinx.Graphics.OpenGL;
+using Ryujinx.UI.Common.Configuration;
+using SPB.Graphics;
+using SPB.Graphics.Exceptions;
+using SPB.Graphics.OpenGL;
+using SPB.Platform;
+using SPB.Platform.WGL;
+using SPB.Windowing;
+using System;
+
+namespace Ryujinx.Ava.UI.Renderer
+{
+    public class EmbeddedWindowOpenGL : EmbeddedWindow
+    {
+        private SwappableNativeWindowBase _window;
+
+        public OpenGLContextBase Context { get; set; }
+
+        protected override void OnWindowDestroying()
+        {
+            Context.Dispose();
+
+            base.OnWindowDestroying();
+        }
+
+        public override void OnWindowCreated()
+        {
+            base.OnWindowCreated();
+
+            if (OperatingSystem.IsWindows())
+            {
+                _window = new WGLWindow(new NativeHandle(WindowHandle));
+            }
+            else if (OperatingSystem.IsLinux())
+            {
+                _window = X11Window;
+            }
+            else
+            {
+                throw new PlatformNotSupportedException();
+            }
+
+            var flags = OpenGLContextFlags.Compat;
+            if (ConfigurationState.Instance.Logger.GraphicsDebugLevel != GraphicsDebugLevel.None)
+            {
+                flags |= OpenGLContextFlags.Debug;
+            }
+
+            var graphicsMode = Environment.OSVersion.Platform == PlatformID.Unix ? new FramebufferFormat(new ColorFormat(8, 8, 8, 0), 16, 0, ColorFormat.Zero, 0, 2, false) : FramebufferFormat.Default;
+
+            Context = PlatformHelper.CreateOpenGLContext(graphicsMode, 3, 3, flags);
+
+            Context.Initialize(_window);
+            Context.MakeCurrent(_window);
+
+            GL.LoadBindings(new OpenTKBindingsContext(Context.GetProcAddress));
+
+            Context.MakeCurrent(null);
+        }
+
+        public void MakeCurrent(bool unbind = false, bool shouldThrow = true)
+        {
+            try
+            {
+                Context?.MakeCurrent(!unbind ? _window : null);
+            }
+            catch (ContextException e)
+            {
+                if (shouldThrow)
+                {
+                    throw;
+                }
+
+                Logger.Warning?.Print(LogClass.UI, $"Failed to {(!unbind ? "bind" : "unbind")} OpenGL context: {e}");
+            }
+        }
+
+        public void SwapBuffers()
+        {
+            _window?.SwapBuffers();
+        }
+
+        public void InitializeBackgroundContext(IRenderer renderer)
+        {
+            (renderer as OpenGLRenderer)?.InitializeBackgroundContext(SPBOpenGLContext.CreateBackgroundContext(Context));
+
+            MakeCurrent();
+        }
+    }
+}