Small OpenGL Renderer refactoring (#177)

* Call OpenGL functions directly, remove the pfifo thread, some refactoring

* Fix PerformanceStatistics calculating the wrong host fps, remove wait event on PFIFO as this wasn't exactly was causing the freezes (may replace with an exception later)

* Organized the Gpu folder a bit more, renamed a few things, address PR feedback

* Make PerformanceStatistics thread safe

* Remove unused constant

* Use unlimited update rate for better pref

Ryujinx.HLE/Switch.cs

@@ -71,6 +71,11 @@ namespace Ryujinx.HLE
             Os.LoadProgram(FileName);
         }
 
+        public void ProcessFrame()
+        {
+            Gpu.Fifo.DispatchCalls();
+        }
+
         internal virtual void OnFinish(EventArgs e)
         {
             Finish?.Invoke(this, e);