title: laravel 5.8 Auth/RegisterController custom redirect on validation failure
body: <p>I'm using Laravel 5.8, I have a single page that has both the Registration and Login forms (2 separate forms posting to the respective endpoints/controllers)</p>
  
  <p>My Registration Form posts to the Auth/RegistrationController as provided by Lavarel Auth.</p>
  
  <p>I would like to change the behaviour so that on an unsuccessful registration attempt it will add an additional parameter to redirect url so I know which form to apply to validation feedback too.</p>
  
  <p>I'm already aware of the redirectTo variable this appears to be for successful requests though</p>