Add a way to prevent textarea to get the maximize link

Adding a textarea in xwiki automatically lead to getting a "maximize" link on the textarea to be able to use it in fullscreen.
This mechanism should have an opt-out: right now, the only way to disable this link is actually to hide it with a css. On the contrary we should have a way to prevent the textarea to get the new behaviour.
We could either:

• exclude textareas that have some other class (like "no-fullscreen" or whatever)
• exclude textarea that are inside a container that has some class