title: .net core Identity, getting meaningful login failed reason
body: <p>When a login fails, I wish to know if it was the username, the password or something else.</p>
  
  <pre><code>var signinResult = await _signInManager.PasswordSignInAsync(
      loginViewModel.UserName,
      loginViewModel.Password,
      false, false);
  </code></pre>
  
  <p>returns SignInResult which just tells me that it's NotAllowed.</p>
  
  <p>Can I get a more meaningful reason from Identity somehow?</p>