Fullscreen: "exitFullscreen" leads to "Document not active" JS error in Chrome 71

Hi @artf ,

Thanks for all your work with grapesjs.

I've been integrating your editor for a few months now, and I've just discovered that using the Fullscreen button in Chrome 71 leads to a "Document not active" error in the JavaScript console:

grapes.min.js?v0.14.43:3 Uncaught (in promise) TypeError: Document not active at i.disable (grapes.min.js?v0.14.43:3) at i.stop (grapes.min.js?v0.14.43:3) at i.callStop (grapes.min.js?v0.14.43:3) at Object.stopCommand (grapes.min.js?v0.14.43:12) at i.updateActive (grapes.min.js?v0.14.43:12) at m (grapes.min.js?v0.14.43:2) at v (grapes.min.js?v0.14.43:2) at h (grapes.min.js?v0.14.43:2) at i.c.trigger (grapes.min.js?v0.14.43:2) at i.set (grapes.min.js?v0.14.43:2)

This seems to be quite recent, and happens with your online Newsletter demo: https://grapesjs.com/demo-newsletter-editor.html

Just click on the Fullscreen button, and you should get the error as well.

The same issue has been reported on another GitHub project: https://github.com/jpilfold/ngx-image-viewer/issues/23

A workaround seems to check whether fullscreen mode is active or not (eg. document.fullscreen, window.fullScreen). I tried this with grapesjs, if I check this before running or stopping the fullscreen command, there are less errors, but there's still an error while calling disable() from fsChanged() in the Fullscreen module code:

grapes.js Uncaught (in promise) TypeError: Document not active at child.disable (grapes.js:27755) at child.stop (grapes.js:27787) at child.fsChanged (grapes.js:27769)

Hope you'll have enough information to investigate. Feel free to ask if necessary!