Layers dropdown menu order fix

[zivfi-ma]

small quality-of-life suggestion:

a lot of times we (tech-art) need to assign a layer to a node, and we choose it from a dropdown menu (red square).
the thing is, the layers inside the dropdown menu aren't necessary organized in the right order (which you can see at the top part of the screenshot).
it'll be nice if the dropdown will match the actual layer order :)