Put screen effects render handling inside a function

This de-duplicates the screen effects rendering code by putting it
inside a function, Graphics::renderwithscreeneffects(), and using that
instead of copy-pasted code.

desktop_version/src/editor.cpp

@@ -3422,19 +3422,7 @@ void editorrender()
 
     graphics.drawfade();
 
-    if (game.flashlight > 0 && !game.noflashingmode)
-    {
-        graphics.flashlight();
-    }
-
-    if (game.screenshake > 0  && !game.noflashingmode)
-    {
-        graphics.screenshake();
-    }
-    else
-    {
-        graphics.render();
-    }
+    graphics.renderwithscreeneffects();
 }
 
 void editorlogic()