Once added, we don't know if a node property is json or string
When we are adding a node property, it's easy to check that the parameter is json or string. There is a validator for that.
But once added, we don't know anymore. And since we are not able to edit a parameter (arg), we can't know ever if Rudder think it's a string or json.
We need to:
- know in the backend what it is,
- display a capsule [json] or [string] depending on that information.