feat: Handle instagram test service (#11244)

This PR will handle the Instagram test events. We are using the last
created Instagram channel as the test channel since we don't have any
other channels for testing purposes at the time of Meta approval.



https://github.com/user-attachments/assets/98302b7a-d72c-4950-9660-861a5e08d55f

---------

Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>
Co-authored-by: Shivam Mishra <scm.mymail@gmail.com>

spec/factories/instagram/instagram_message_create_event.rb

@@ -361,4 +361,34 @@ FactoryBot.define do
     end
     initialize_with { attributes }
   end
+
+  factory :instagram_test_event, class: Hash do
+    entry do
+      [
+        {
+          'id': '0',
+          'time': '2021-09-08T06:34:04+0000',
+          'changes': [
+            {
+              'field': 'messages',
+              'value': {
+                'sender': {
+                  'id': '12334'
+                },
+                'recipient': {
+                  'id': '23245'
+                },
+                'timestamp': '1527459824',
+                'message': {
+                  'mid': 'random_mid',
+                  'text': 'random_text'
+                }
+              }
+            }
+          ]
+        }
+      ]
+    end
+    initialize_with { attributes }
+  end
 end