Adapt ABI format to use object instead of array

[arboleya]

Dependent on:

• Hash based ABI & Indexer support sway#5951

Preliminary format:

{
  "types": { // changed from array to object
    "0": { // indexes will therefore be strings instead of numbers
      "typeId": "0",
      "type": "(_, _, _)",
      "components": [
        {
          "name": "__tuple_element",
          "type": "1", // changed from number to string
          "typeArguments": null
        },
        {
          "name": "__tuple_element",
          "type": "1",
          "typeArguments": null
        },
        {
          "name": "__tuple_element",
          "type": "1",
          "typeArguments": null
        }
      ],
      "typeParameters": null
    }
  },
  ...
}