Avalonia - Couple fixes and improvements to vulkan (#3483)

* drop split devices, rebase

* add fallback to opengl if vulkan is not available

* addressed review

* ensure present image references are incremented and decremented when necessary

* allow changing vsync for vulkan

* fix screenshot on avalonia vulkan

* save favorite when toggled

* improve sync between popups

* use separate devices for each new window

* fix crash when closing window

* addressed review

* don't create the main window with immediate mode

* change skia vk delegate to method

* update vulkan throwonerror

* addressed review

Ryujinx.Graphics.Vulkan/WindowBase.cs

@@ -10,5 +10,6 @@ namespace Ryujinx.Graphics.Vulkan
         public abstract void Dispose();
         public abstract void Present(ITexture texture, ImageCrop crop, Action<object> swapBuffersCallback);
         public abstract void SetSize(int width, int height);
+        public abstract void ChangeVSyncMode(bool vsyncEnabled);
     }
 }