[2.x] Add Password Confirmation as Standalone Feature

[alucic]

This PR attempts to solve this issue #84

Currently, even with all features disabled in the fortify.php configuration file, the confirm password routes are still enabled.

This PR introduces breaking changes by making the confirm password routes disabled by default.
To enable them, you must either:

1. Explicitly enable Features::passwordConfirmation() in the features array of your fortify.php file:

   'features' => [
       // ...
       Features::passwordConfirmation(),
       // ...
   ],

2. Enable two-factor authentication with confirmPassword set to true:

   'features' => [
       // ...
       Features::twoFactorAuthentication([
           'confirmPassword' => true,
       ]),
       // ...
   ],

---

I'm not quite sure how to write tests for this. Updating the config during runtime doesn't work because routes register first

public function test_password_confirmation_routes_not_enabled_if_2fa_confirm_password_is_disabled()
{
    config(['fortify.features' => [
        Features::twoFactorAuthentication([
            'confirmPassword' => false,
        ]),
    ]]);

    $this->assertFalse(Route::has('password.confirm'));
    $this->assertFalse(Route::has('password.confirm.store'));
    $this->assertFalse(Route::has('password.confirmation'));
}

Tested locally 4 cases using php artisan route:list:

1. With Features::passwordConfirmation() -> registers password routes
2. With Features::twoFactorAuthentication(['confirmPassword' => true]) -> registers password routes
3. Without Features::passwordConfirmation()
4. With Features::twoFactorAuthentication(['confirmPassword' => false])