validation schema for field types

Create or design a way to automatically generate a validation JSON schema to validate the fieldTypes specification. This would be useful to
- Validate AI-generated forms, be able to show errors to users or even to send the errors back to the LLM to get a correct response
- Clean up generated forms (remove stuff such as `isRequired` that are intermediate properties that are not used in the final form)
- Group and validate schema settings/ui settings

We should maintain only either fieldTypes or the validation schema. The best way might be to automatically generate the validation schema from fieldTypes via a script.