qt: input_slider: Convert wheel events to KEY_MOUSEWHEEL*

This way we can honor the user's settings regarding inverting the scroll
direction, and they can chose the size of the jump

refs #19790

modules/gui/qt/util/input_slider.cpp

@@ -404,9 +404,9 @@ void SeekSlider::wheelEvent( QWheelEvent *event )
     if( !isSliding && isEnabled() )
     {
         if ( event->delta() > 0 )
-            var_SetInteger( p_intf->obj.libvlc, "key-action", ACTIONID_JUMP_BACKWARD_SHORT );
+            var_SetInteger( p_intf->obj.libvlc, "key-pressed", KEY_MOUSEWHEELRIGHT );
         else
-            var_SetInteger( p_intf->obj.libvlc, "key-action", ACTIONID_JUMP_FORWARD_SHORT );
+            var_SetInteger( p_intf->obj.libvlc, "key-pressed", KEY_MOUSEWHEELLEFT );
     }
     event->accept();
 }