request: support mapping external types to internal input types

[sandrina-p]

Problem

Reported at #73 by @juicycleff

Json Schema Form supports internal types and treats them quite differently eg. group-array. If a system requires multiple kind of components to be treated internally as group-array, this would be impossible.

Proposals

Proposal 1

Adds support for mapping external input types as group array eg.

const headlessFormOutput = createHeadlessForm(schema, {
    ...,
    presentationMapping: {
      groupArray: ["array", "conditions"],
    }
  })

Proposal 2 (final solution)

To make sure I understood, you have a JSON Schema with a different presentation.inputType (let's say "conditions") and you want it to be treated as if it was "group-array", is that it?
Let me give another example to double-check, imagine a JSON Schema with a field of "inputType: "digits" that we want to treat as "number", like this:

{
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "age": {
      "title": "Your age",
      "x-jsf-presentation": {
        "inputType": "digits" // <-- note how it's "digits" instead of "number"
      }
    }
  }
}

Is that the type of customization you are trying to support? f so, we could reuse the existing config inputTypes and create a new attr "altName" (or any other name) to map the alternative names, like this:

const headlessFormOutput = createHeadlessForm(schema, {
    inputTypes: {
      "group-array": {
         altName: ["array", "conditions"] // <!-- New!
     },
      "number": {
         altName: ["digits"] // <!-- New!
     },
    }
  })