Fix streaming interface to parseCSV

[josephjclark]

Summary

This PR adds a couple of tiny fixes to support CSV streaming, plus a couple of unit tests to show the expected usage.

Details

There were a couple of wee problems with the streaming API:

1. Expand references was trying to expand streams. Naughty.
2. You can't pass response.body straight into csv-parse. response.body is a browser-compliant ReadableStream, but we need it to be a node Readable. Subtle. All we have to do is call Readable.from to convert the stream to a compatible API
3. The callback was always invoked after the final chunk - even if it's passing an empty chunk. Not a big deal but I thought I'd drop a fix.

There are tests in index.test.js which show streaming working from the filesystem and from unidici request. I have also tested this without a mock (ie, host a csv file locally with npx serve, pull it down with node native fetch, and parse it) - but obviously there's no use commiting that. I am satisfied that the mock exercises the same API.

@mtuchi I think you should probably merge this into your msgraph work for akf. You should be able to stream freely from there.

[mtuchi]

Thanks @josephjclark this looks good 👍🏽 , I have reviewed and tested the implementation,
Tiny changes i added import {Readable} from 'node:stream' in Adaptors.js Since it's being used in parseCsv and the job was failing when i tried to use parseCsv
and i have remove import {Readable} from 'node:stream' in test.js since it was not being used.