chore: update importer to only output unixfs things

[achingbrain]

BREAKING CHANGE:

If you specify raw-nodes to be true or cid-version to be 1 and your data fits in one chunk, you would previously get a CID that resolves to an ipld-raw node.

Now you will get a CID that resolves to a dag-pb node, so the output of every import will be a unixfs object.

[achingbrain]

Refs #2696

[alanshaw]

Just double checking: rawNodes => rawLeaves?

I think this is a good idea. It will cause an interop issue with go-ipfs because CIDs will be different for the same data (when cidVersion is 1 or rawLeaves is true). Someone will probably raise this as a problem if go-ipfs doesn't catch up quickly. So, I just wanted to check there's consensus on this with the go-ipfs team and that there is an issue to track it that we can point people at when it is reported?

Will you also check there is an interop test for this (albeit skipped for now)? 🙏

[achingbrain]

check there's consensus on this with the go-ipfs team

This change is in line with @Stebalien's comment here: ipfs-inactive/js-ipfs-unixfs-importer#44 (comment) so I believe there is consensus 😉

and that there is an issue to track it that we can point people at when it is reported?

Right here: ipfs/kubo#6940

Will you also check there is an interop test for this (albeit skipped for now)?

Here: ipfs/interop#105

Kind of an aside but I think we should move most of those interop tests to the interface suite - I think the interop tests should be focused on networking type stuff between go, js, rust etc. E.g. bitswap, the dht, pubsub, etc.