Revert "refactor: move deSEC password-reveal logic from JS to Twig (PRG pattern)"

This reverts commit 1c6ca098d5.

php/src/Desec/DesecManager.php

@@ -122,7 +122,10 @@ class DesecManager {
         if ($code === 400) {
             $data = json_decode($body, true, 512, JSON_THROW_ON_ERROR);
             if (is_array($data) && isset($data['email'])) {
-                throw new AlreadyRegisteredException($email);
+                throw new \Exception(
+                    'This email address is already registered at deSEC. '
+                    . 'If this is your account, please enter your deSEC password in the password field and try again.',
+                );
             }
             throw new \Exception('Registration at deSEC failed (HTTP 400): ' . $body);
         }