De-duplicate Graphics::drawmenu() and Graphics::drawlevelmenu()

Graphics::drawmenu() no longer has copy-pasted code for each individual
case. Instead, the individual cases have their own adding on to common
code, which is far easier to maintain.

Also, the only difference Graphics::drawlevelmenu() does is in some
y-positioning stuff. There's no reason to make it a whole separate
function and duplicate everything AGAIN. So it's been consolidated into
Graphics::drawmenu() as well, and I've added a boolean to draw a menu
this way if it's the level menu.

desktop_version/src/Render.cpp

@@ -1188,14 +1188,7 @@ void titlerender()
         if(tg>255) tg=255;
         if (tb < 0) tb = 0;
         if(tb>255) tb=255;
-        if (game.currentmenuname == Menu::levellist)
-        {
-            graphics.drawlevelmenu(tr, tg, tb);
-        }
-        else
-        {
-            graphics.drawmenu(tr, tg, tb);
-        }
+        graphics.drawmenu(tr, tg, tb, game.currentmenuname == Menu::levellist);
     }
 
     graphics.drawfade();