[v2] consistant submission success flow for forms inside modals

[manV]

Describe the bug On the integration addition form, we are not closing the modal or showing success message.

To Reproduce Steps to reproduce the behavior:

1. Go to integrations
2. Click on 'add new integration'
3. Submit the form
4. Modal doesn't close and it also doesn't show success message

Expected behavior It should show success message.

Components/Services affected

• [x] UI/Frontend
• [ ] API/Backend
• [ ] Agent
• [ ] Deployment/YAMLs
• [ ] CI/CD Integration
• [ ] Other (specify)

Additional context Add any other context about the problem here.