Adding copilot IVA requests to posting

copilot/posting/copilotux/IVA/authentication.posting.yaml

@@ -0,0 +1,19 @@
+name: Authentication
+method: POST
+url: $TOKEN_URL
+body:
+  form_data:
+  - name: grant_type
+    value: client_credentials
+  - name: audience
+    value: api://vcp/wa-cloudevent
+  - name: client_id
+    value: $CLIENT_ID_V2
+  - name: client_secret
+    value: $CLIENT_SECRET_V2
+  content_type: application/x-www-form-urlencoded
+headers:
+- name: content-type
+  value: application/x-www-form-urlencoded
+scripts:
+  on_response: authorization.py