Custom API Support

[bh2smith]

Adding Custom API class and field to DuneClient. There is a skipped test that does run when not ignored (but its specific to user name).

Sample usages was added to the README:

const { DUNE_API_KEY } = process.env;

const client = new DuneClient(DUNE_API_KEY ?? "");
const results = await client.custom.getResults({
  username: "your_username", 
  slug: "endpoint-slug"
  // optional arguments: see `GetResultParams`
  limit: 100,
});

[philippWassibauer]

tested it locally, works.
We probably need to change the reference to username as it might be misleading for teams. Will come back on that and change if necessary

[bh2smith]

So is that an approval to merge? If so, can you click it?

We might also be able to fetch the user name from the query id with get query, but then the user would have to specify that and it might cost more credits.

[philippWassibauer]

I added the small changes now. I can merge it. Maybe just have a last look over my changes