fix: Add fixes for sentry errors (#3522)

- Add fixes for sentry errors

app/views/mailers/agent_notifications/conversation_notifications_mailer/conversation_mention.liquid

@@ -5,6 +5,7 @@
   {{message.text_content}}
 </blockquote>
 
+<p><b>Previous messages:</b></p>
 {% for chat_message in conversation.recent_messages %}
   <div>
     {% if chat_message.sender == user.available_name %}
@@ -15,7 +16,7 @@
   </div>
 
   <div>
-    <p style="padding: 10px 20px; margin: 5px 0 20px 0; background: #F2F3F7; border-radius: 10px; display: inline-block; font-family: "Helvetica Neue",Tahoma,Arial,sans-serif; text-align: start; unicode-bidi: plaintext;">
+    <p style="padding: 10px 20px; margin: 5px 0 20px 0; background: #F2F3F7; border-radius: 10px; display: inline-block; text-align: start; unicode-bidi: plaintext;">
       {% if chat_message.content %}
         {{chat_message.content}}
       {% endif %}
@@ -28,5 +29,6 @@
     </p>
   </div>
 {% endfor %}
-
-<p><a href="{{ action_url }}">View Message</a></p>
+<p>
+  <a href="{{ action_url }}">View Message</a>
+</p>