Fix: attachment name for incoming messages

Use original_filename to get the name of the file attached to the message.

Had to add the message_type method to the WhatsApp/incoming_message_service due to the Assignment Branch Condition linter error for the attach_files method.

Fixes #4183

app/services/telegram/incoming_message_service.rb

@@ -105,7 +105,7 @@ class Telegram::IncomingMessageService
       file_type: file_content_type,
       file: {
         io: attachment_file,
-        filename: attachment_file,
+        filename: attachment_file.original_filename,
         content_type: attachment_file.content_type
       }
     )