Fix menu that you land on when you complete game or custom level

When you complete the game, you're now redirected to the play menu. This
is because your quicksave will have been deleted so you can't go back to
the summary menu.

When you complete a custom level, you'll go back to the levels list, in
case you started the level from a quicksave.

desktop_version/src/Game.cpp

@@ -2105,6 +2105,7 @@ void Game::updatestate()
                 if(!muted && ed.levmusic>0) music.fadeMusicVolumeIn(3000);
             }
             graphics.showcutscenebars = false;
+            returntomenu(Menu::levellist);
             break;
 #endif
         case 1014:

desktop_version/src/Logic.cpp

@@ -109,6 +109,7 @@ void gamecompletelogic2()
         game.gamestate = TITLEMODE;
         graphics.fademode = 4;
         music.playef(18);
+        game.returntomenu(Menu::play);
         game.createmenu(Menu::gamecompletecontinue);
         map.nexttowercolour();
     }