fix: Add fixes for sentry errors (#3522)

- Add fixes for sentry errors

app/drops/conversation_drop.rb

@@ -13,7 +13,7 @@ class ConversationDrop < BaseDrop
     @obj.try(:recent_messages).map do |message|
       {
         'sender' => message_sender_name(message.sender),
-        'content' => transform_user_mention_content(message.content),
+        'content' => render_message_content(transform_user_mention_content(message.content)),
         'attachments' => message.attachments.map(&:file_url)
       }
     end

app/drops/message_drop.rb

@@ -6,7 +6,7 @@ class MessageDrop < BaseDrop
   end
 
   def text_content
-    content = @obj.try(:content)
-    transform_user_mention_content content
+    content = @obj.try(:content) || ''
+    render_message_content(transform_user_mention_content(content))
   end
 end