Keep track of how successful fetching directly from IPFS has been

[andrew]

Now that we can fetch packages directly from IPFS by their sha2, it would be neat to see how often those fetches were successful vs falling back to http requests.

The timeout is set to a fairly aggressive 1 second right now, so we may even timeout if the content is available on IPFS, in theory the more nodes hosting the content the more likely the IPFS requests will succeed.