Use new login and register endpoints

[umitcan07]

🧱 Description

Here is a good frontend issue for you: We need to implement new backend endpoints for login and register. Modify the Login.data.tsx and Register.data.tsx so that they are now compatible with the new media type and new endpoints. We should be using {{BASE_URL}}/api/v2/

To be reviewed by: @umitcan07

🛣️ Reproduction

Go to login and register. They will be using wrong media type and wrong endpoints

📋 Acceptance Criteria

• [x] Login and Register actions works properly with the new backend

[umitcan07]

:) my man does it all