[Question] How to change centered layout on specific page ?

Hi! 👋

I have a question about the `nb-layout` and in particular about the `center` option. With this option, we have this behavior (according to the documentation):

> 📝 The layout content (columns) becomes centered when the window width is more than the value specified in the theme variable layout-content-width.

How can we have pages with a full width content with this configuration?

Of course, I don't wish to duplicate the layout structure on each component!

Let's take a simple example of a layout present in the `app.component.html`:
```html

```

I have a solution but I don't like it.
I could use the router (url or data) to set the `center` option.

--
I add another case: being able to add columns in a child component.
For example, if my route display this component template:
```html

First column

Second column

```
This is not possible because `nb-layout-column` is not allowed in depth.
And I can't remove `nb-layout-column` from the `app.component` because the `router-outlet` seems to be not allowed as first child (`nb-layout` > `router-outlet`)

--

What is the best solution to do this?
Thank you for your feedback 😃