Steps to reproduce

1. Log in to back office.
2. Go to Content / Media.
3. Start creating an Image content.
4. On create Image form, click in 'Caption' field and input image (it will trigger image-picker).
5. In image picker, click on 'Create folder inside Media' button.
6. Fill folder name with very long name.

Actual result:

An error 400 bad request occurs.

POST https://127.0.0.1:8000/api/ibexa/v2/content/objects 400 (Bad Request)

Expected result:

Validation block user to create a folder with long name to configured number of characters 255.