UI: Add Metal surface creation for MoltenVK (#3980)

* Initial implementation of metal surface across UIs

* Fix SDL2 on windows

* Update Ryujinx/Ryujinx.csproj

Co-authored-by: Mary-nyan <thog@protonmail.com>

* Address Feedback

Co-authored-by: Mary-nyan <thog@protonmail.com>

Ryujinx.Headless.SDL2/Program.cs

@@ -77,6 +77,26 @@ namespace Ryujinx.Headless.SDL2
             _accountManager = new AccountManager(_libHacHorizonManager.RyujinxClient);
             _userChannelPersistence = new UserChannelPersistence();
 
+            if (OperatingSystem.IsMacOS())
+            {
+                AutoResetEvent invoked = new AutoResetEvent(false);
+
+                // MacOS must perform SDL polls from the main thread.
+                Ryujinx.SDL2.Common.SDL2Driver.MainThreadDispatcher = (Action action) =>
+                {
+                    invoked.Reset();
+
+                    WindowBase.QueueMainThreadAction(() =>
+                    {
+                        action();
+
+                        invoked.Set();
+                    });
+
+                    invoked.WaitOne();
+                };
+            }
+
             _inputManager = new InputManager(new SDL2KeyboardDriver(), new SDL2GamepadDriver());
 
             GraphicsConfig.EnableShaderCache = true;