feat: change continuation email body to use a translation key

module/Email/view/email/en_GB/html/email-inbox-reminder-continuation.phtml

@@ -1,6 +1,6 @@
-<p>Dear operator,</p>
+<?php echo $this->translate('email.inbox-reminder-continuation-html.body'); ?>
 
-<?php echo $this->translate('email.inbox-reminder-continuation.body'); ?>
+<p>Licence: <?php echo $this->escapeHtml($this->licNo) . ' ' . $this->escapeHtml($this->operatorName); ?></p>
 
 <p>
     <a href="<?php echo $this->escapeHtml($this->url); ?>">Sign in to your account</a>

module/Email/view/email/en_GB/plain/email-inbox-reminder-continuation.phtml

@@ -1,11 +1,5 @@
-Dear operator,
+<?php echo $this->translate('email.inbox-reminder-continuation-plain.body'); ?>
 
-We have sent an e-mail to you recently advising that a document relating to your Operator's Licence continuation for <?php echo $this->licNo . ' ' . $this->operatorName; ?> has been placed in your Operator Self Service inbox.
-
-We note that this has not yet been read. Please log on to view the correspondence as soon as possible.
-
-Please note that you must print off the continuation document, sign it and return it to the office as soon as possible, highlighting any changes to the details on the document.
-
-Failure to return the document will result in the termination of your operator licence.
+Licence: <?php echo $this->licNo . ' ' . $this->operatorName; ?>
 
 Sign in to your account at <?php echo $this->url; ?>.