[RFC][HttpKernel][Security] Allowed adding attributes on controller arguments that will be passed to argument resolvers.

[jvasseur]

Q	A
Branch?	master
Bug fix?	no
New feature?	yes
Deprecations?	no
Tickets	Fix #29692
License	MIT
Doc PR	Not yet, will do it it this PR is accepted.

This PR allow to configure argument resolvers using PHP8 attributes.

This is basically a fix for #29692 but using a different strategy that the one proposed in the issue:

• it uses PHP attributes instead of doctrine annotation since they can be added directly on method arguments.
• it uses a simpler design by just adding the attribute to the ArgumentMetadata and let the individual resolvers decide if they want to react to the presence of the attribute.
• it uses an attributes classe per use-case instead of an unique Arg annotation.

As an example, I've added (in the second commit) a CurrentUser attribute that allows the UserValueResolver to always inject the current user even if the argument is not typed with the UserInterface (to allow typing your actual class instead for example).

This would allow to do things like this:

class MyController
{
    public function indexAction(#[CurentUser] MyUser $user)
    {
    }
}

[fabpot]

/cc @derrabus

[fabpot]

I'm going to play with it a little but the code LGTM.

[fabpot]

Thank you @jvasseur.

[derrabus]

Great addition, thanks @jvasseur!