Show a warning when certain types of map layers are located "above" the image

[Glodenox]

It sometimes happens that other userscripts add map layers that are positioned above the image. This can be solved by adjusting the parent layer of that image, but this is not always as easy to see for the user.

An event listener could be added to the "layeradded" event of the map which will check whether any such layers are located above the currently active image. If so, it could show a small warning message in the tab indicating this potential issue and how to solve this.