We should add a fullscreen button, that will open a popup with the content of the tool.

It can be a real popup : so we close the tool but the button is still down while the popup is still open, and the popup could have a button to go back as a tab.
It can juste be a new tab : so we close the tool, but the button is now up as help was not opened... this would imply opening many time the same help...