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

[MartinPutz]

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.

[artf]

Should be fixed in this branch https://github.com/artf/grapesjs/tree/multi-frame
Multi framing is still far from being complete but I hope to merge soon that branch (big canvas refactoring but without breaking changes), definitely not for this release (should be published this days) but probably in the next one.

[artf]

I close this issue as I'm planning to solve all ones related to absolute positioning here: #3770