Keep positions of classes readded back to canvas

[RadStr]

Currently when class is removed from canvas, it is also removed from visual model, therefore when we put it back again, it won't be put at the same position as it was on before the removal.

To solve this we can store positions of classes removed from canvas in some storage, for example

• session storage
• local storage

and use those stored positions, when we add the class back to canvas.

Example of not keeping positions after readding back to canvas: