feat: SAML authentication controllers [CW-2958] (#12319)

enterprise/app/helpers/saml_authentication_helper.rb

@@ -0,0 +1,12 @@
+module SamlAuthenticationHelper
+  def saml_user_attempting_password_auth?(email, sso_auth_token: nil)
+    return false if email.blank?
+
+    user = User.from_email(email)
+    return false unless user&.provider == 'saml'
+
+    return false if sso_auth_token.present? && user.valid_sso_auth_token?(sso_auth_token)
+
+    true
+  end
+end