Tidying/General quality of life updates

General quality of life updates:

- Ticket contact edit: 'No one' should be logged when ticket isn't associated with any contact, rather than a blank space; also fix email content
- Ticket portal/guest: Only show 'Assigned to' if someone is actually assigned
- Ticket tasks: Don't allow adding/modifying tasks for tickets in a resolved state
- Portal contacts: Properly align word 'Contacts' in a similar way all other page headings are aligned
- Client PDF export/handover: Now opens in a new self-closing window

portal/contacts.php

@@ -17,8 +17,10 @@ $contacts_sql = mysqli_query($mysqli, "SELECT contact_id, contact_name, contact_
 ?>
 
     <div class="row">
-        <h3>Contacts</h3>
-        <div class="col offset-7">
+        <div class="col">
+            <h3>Contacts</h3>
+        </div>
+        <div class="col offset-6">
             <a href="contact_add.php" class="btn btn-primary" role="button"><i class="fas fa-plus mr-2"></i>New Contact</a>
         </div>
     </div>