perf: refactor Auth

[kenjis]

Description
See #905 (reply in thread)

• to reduce the number of loaded files
  • in the current code, service('auth')->routes($routes) creates Authentication and UserModel instances.

Before:

After:

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[datamweb]

@kenjis, we can use command php spark sheild:setup to set the value of $collectors. In this way, we allow the user to cancel the load of Auth collector in Debugbar even in the mode of development. Why not act like what we did for the helpers!

OR
Config/Auth.php:

/**
* --------------------------------------------------------------------
* Load of Auth collector in Debugbar
* --------------------------------------------------------------------
* By default, Auth in Debugbar is loaded in mode `development`. 
* If you want Auth in Debugbar not to be loaded even in `development` mode,
* set the `false`.
*/
public bool $showAuthInDebugbar = true;

Config/Registrar.php:

    public static function Toolbar(): array
    {
        return (config('Auth')->showAuthInDebugbar) ?
        [
            'collectors' => [
                Auth::class,
            ],
        ] : [];
    }

[datamweb]

And another thing that got me thinking is if we can check if the file APPPATH\Config\Auth.php exists, if it does then the file VENDORPATH\codeigniter4\shield\src\Config\Auth.php does not load
Is this reasonable?

[kenjis]

Config\Auth extends Shield\Config\Auth. So both are always loaded.

[datamweb]

LGTM!
I fell in love with this PR 😊.