"Delete section" processor doesn't kills invisible objects

[Wohlstand]

While investigating the issue that level makes crashes at SMBX2 game, the Editor side bug was found: https://github.com/WohlSoft/Moondust-Project/blob/master/Editor/main_window/level/level_sections_mods.cpp#L321-L326

The author of the original issue noticed that the "delete section" option was been used to remove sections and all items on them. However, there are was several invisible objects that weren't been deleted, and they caused the crash of the SMBX2 game.

After quick checking the Qt documentation: https://doc.qt.io/qt-5/qgraphicsscene.html#items-1 was found, that the items() call returns VISIBLE items only which is a direct source of the problem.

[Wohlstand]

The bug has been fixed, need to ask the reporter to test the updated Editor.

[Wohlstand]

Quickly closing as there is no feedback from an original author for a while.