Update resend confirmation flow with improved messaging

Improve the resend confirmation flow by:
- Consolidating multiple status messages into a single generic response
- Adding HTML support for the result message
- Moving the instruction text after the message display
- Simplifying the PHP logic by removing redundant checks
- Making the messaging more privacy-conscious by not revealing email
  existence
- Adding a link to sign again in the result message

The changes follow the project's minimal PHP philosophy while improving
user experience and security.

content/underskriftskampanje/medisinsk-cannabis-pa-resept/send-bekreftelse-pa-nytt/01-content.php

@@ -1,12 +1,15 @@
 <h1>Send bekreftelse på nytt</h1>
 
-<p>Skriv inn e-postadressen du brukte da du signerte, så sender vi en ny bekreftelseslenke.</p>
-
 <?php if (!empty($petition_resend_message)): ?>
 <div class="form-message form-message--<?= htmlspecialchars($petition_resend_message['type']) ?>" role="alert">
+    <?php if (!empty($petition_resend_message['html'])): ?>
+    <p><?= $petition_resend_message['text'] ?></p>
+    <?php else: ?>
     <p><?= htmlspecialchars($petition_resend_message['text']) ?></p>
+    <?php endif; ?>
 </div>
-<?php endif; ?>
+<?php else: ?>
+<p>Skriv inn e-postadressen du brukte da du signerte, så sender vi en ny bekreftelseslenke.</p>
 
 <form method="post" action="" class="resend-form">
     <div class="form-group">
@@ -17,5 +20,6 @@
         <button type="submit" name="petition_resend" class="button">Send på nytt</button>
     </div>
 </form>
+<?php endif; ?>
 
 <p><a href="../">Tilbake til underskriftskampanjen</a></p>