System: Add a new throttler/pacer which can catch up on lost time

This can result in worse frame pacing, so if you have a decent machine
you'll probably want to turn on "display all frames" in display
settings.

But, it's sadly needed for Android.

src/duckstation-sdl/sdl_host_interface.cpp

@@ -1856,7 +1856,11 @@ void SDLHostInterface::Run()
 
     if (System::IsRunning())
     {
-      System::RunFrame();
+      if (m_display_all_frames)
+        System::RunFrame();
+      else
+        System::RunFrames();
+
       UpdateControllerRumble();
       if (m_frame_step_request)
       {