Drag and drop from the toolbox to the editor doesn't work in 11.2

[Tadelsucht]

If a node from the toolbox is dragged to the editor, it doesn't add the node to the editor.

The problem seems to be the targetContext in DrawingDropHandler.cs.
In version 11.1.0, the targetContext is DrawingNodeViewModel, and it can validate the node.

In version 11.2, the targetContext is instead MainViewViewModel. The if statement, and therefore the validation, return false.