fix: check Graphsync retrievals too

[bajtos]

When the storage provider does not advertise HTTP retrieval, but advertises Grapsync retrievals, then let's perform the retrieval check.

This was my original intention when I implemented IPNI querying.

I discovered the problem by accident while working on #55. Unfortunately, there is no easy way how to write a reliable automated test for this, as we would need a CID that's guaranteed to have only Graphsync advertised to IPNI.

FWIW, we want to move to testing HTTP retrievals only and drop support for Graphsync (see #46). However, since we are not there yet, I feel this bug is still worth fixing.

Here is a script I used to verify the fix manually. Please not you need to include changes from #55 to be able to reproduce the problem.

import Spark from './lib/spark.js'

const spark = new Spark()
const stats = {
  byteLength: 0
}

await spark.executeRetrievalCheck({
  cid: 'bafybeidkqbga5lsv4b7uhp2lyvuqsx7topvawtsn7ypej3lz44abs55wfu',
  minerId: 'f02055540'
}, stats)

console.log('\nSTATS\n', stats)

[juliangruber]

Suggested change

	if (indexerResult !== 'OK' && indexerResult !== 'HTTP_NOT_ADVERTISED') return
	if (!(indexerResult === 'OK' || indexerResult === 'HTTP_NOT_ADVERTISED')) return

I find this more understandable: Skip if the indexer result isn't ok or http_not_advertised. Alternatively:

Suggested change

	if (indexerResult !== 'OK' && indexerResult !== 'HTTP_NOT_ADVERTISED') return
	if (!['OK', 'HTTP_NOT_ADVERTISED'].includes(indexerResult)) return

[bajtos]

Makes sense. I decided to extract a named variable to make this even easier to understand.

    const providerFound = indexerResult === 'OK' || indexerResult === 'HTTP_NOT_ADVERTISED'
    if (!providerFound) return

I addressed your comment