[12.x] Allowing Context Attribute to Interact with Hidden

[devajmeireles]

In addition to #55760

---

The PR #55760 implements the {very useful} #[Context] attribute to interact with Context. However, the addition left out something extremely important when we're talking about Context: the hidden items. I would venture to say that hidden items are used more than common ones.

This PR implements the ability to retrieve hidden items by passing the parameter hidden as true. Thanks to modern PHP's named attributes, we can do something similar to what we find in the docs for things like Livewire:

final class CreateUserAction
{
    public function __construct(#[Context('user', hidden: true)] User $user)
    {
        // ...
    }
}

I thought about creating a second {HiddenContext} attribute, but IMHO it would be too much. A property like hidden serves us very well in this case. Thoughts?