feat: Add AI credit topup flow for Stripe (#12988)

Co-authored-by: Shivam Mishra <scm.mymail@gmail.com>
Co-authored-by: Pranav <pranav@chatwoot.com>

app/javascript/dashboard/api/enterprise/account.js

@@ -23,6 +23,10 @@ class EnterpriseAccountAPI extends ApiClient {
       action_type: action,
     });
   }
+
+  createTopupCheckout(credits) {
+    return axios.post(`${this.url}topup_checkout`, { credits });
+  }
 }
 
 export default new EnterpriseAccountAPI();