RFE: Allow to extend properties in leaf nodes

[rgordill]

Hi.

I used the values.schema.json for a tool that creates a form to fill the values. It expects something like:

        "properties": {
            "size": {
                "type": "string",
                "title": "Volume Size",
                "form": true,
                "render": "slider",
                "sliderMin": 1,
                "sliderMax": 2048,
                "sliderUnit": "Gi"
            }

But the properties annotation will create a nested properties in the size property, not the extra "form", "render", etc. It would be extreme useful for this use case to provide a way to define them through annotations.

[rgordill]

It seems similar to the CustomAnnotations, but not just for "x-" ones.