UI - User-friendly JSON fields#33

JSON fields are very good when working on a draft model, or something that’s likely to change very regularly and we don’t want to change the API at every change, or want to try things out fast.

But they’re currently also very unfriendly to non-developers, mostly because we can store tons of stuff there and there is no schema validation, meaning a single misplaced “ can hurt our feelings. (see https://feedback.graphcms.com/32 about that)

The idea would be to use the schema validation to generate a better UI (basically, one input per field), so that editors can use a JSON field similarly to a native GraphCMS field. Obviously, this feature would highly rely on the schema validation to resolve fields types (visual aspect, validation, etc.)

A good first step would be to handle most-used types, such as:

• url
• integer
• string
• decimal
• boolean

Related to #32