Add isResponseDictionary option

[magicmark]

Fixes #1

Support a new isResponseDictionary option in the config.

See the tests for an an example of this in action, but tl;dr:

Example

Resource Response
A dict 😱 ! We couldn't deal with this before:

{
    "2": {
        "foo_id": 2,
        "foo_value": "world"
    },
    "1": {
        "foo_id": 1,
        "foo_value": "hello"
    },
    "3": {
        "foo_id": 3,
        "foo_value": "!"
    }
}

Config:

foo:
    isBatchResource: true,
    docsLink: 'example.com/docs/foos',
    batchKey: 'foo_ids',
    newKey: 'foo_id',
    isResponseDictionary: true,

Dataloader call:

const results = await loaders.foo.loadMany([
  { foo_id: 1 },
  { foo_id: 2 },
  { foo_id: 3 },
]);

Response:

[
    {
        "foo_id": 1,
        "foo_value": "hello"
    },
    {
        "foo_id": 2,
        "foo_value": "world"
    },
    {
        "foo_id": 3,
        "foo_value": "!"
    }
]

---

Thanks @jack-guy for the internal work to drive this!

[ryanruanwork]

shipIt!
@magicmark could you give me access?