[BUG]: Cancelling block drag in IE breaks canvas functionality.

I'm seeing this issue locally and on the GrapesJS demo when using Internet Explorer. If you drag a block over the canvas and attempt to cancel the drag by either dragging the block back to the starting container, or by pressing escape, a new component is still added to the canvas and the canvas highlighting and toolbar stop working. Dragging another block onto the canvas without cancelling it restores the functionality.

Expected Behavior: After dragging a text block over the canvas, pressing escape or returning the block to the block menu should not add a component to the Editor.

Actual behavior: After dragging a text block over the canvas, pressing escape or returning the block to the block menu adds a text component to the editor and the component highlighting and toolbar no longer display.

Steps to Reproduce: Open the GrapesJS HTML demo in Internet Explorer 11. Click the Text block and drag it over the default header section. Without releasing the mouse button, press escape. Or, drag the text block back to it's starting position (observe that the canvas placement cursor does not dissapear) and release the mouse button. Hover your mouse over an existing component in the editor and it will no longer highlight. Click an existing component in the editor and it will not be selected and the toolbar will not be displayed.