[BUG] In absolute dragmode the components are not dropped properly if zoom is applied

Components are not dropped to the exact position if dragmode set to absolute and there is a zoom value applied on the canvas.

GrapesJS version:0.15.8

The issue can be reproduced in the demo as well: https://jsfiddle.net/y8m1x4a3/

Expected behavior: Components can be dropped to the cursor position even if the dragmode is set to absolute and a zoom is applied on the canvas.

Current behavior: When dragmode is absolute and there is a zoom value, the components are dropped away from the cursor position. (the distance/offset depends on the zoom level)

Steps to reproduce:

1. Open jsfiddle above (with editor.Canvas.setZoom(50))
2. Try to add a new text component
3. Check the distance between the cursor position and the component's position.

The distance/offset depends on the zoom value.

The editor.Canvas.setZoom function uses a transform:scale() CSS property and then the 'drop' position is not accurate anymore.