Add support for submitting blobs to a filecoin pipeline

[Gozala]

Context

At the moment most of the filecoin pipeline assumes that all content links are CARs, which may not be the case with Blobs. We need to ensure that blobs can go through filecoin pipeline.

• https://github.com/w3s-project/content-claims/issues/60
• https://github.com/w3s-project/w3up/issues/1407
• https://github.com/w3s-project/w3infra/issues/357

What

Submit blobs to the filecoin pipeline

Why

So that content added as blobs can lands on filecoin

[Gozala]

@vasco-santos I think it would make most sense to just extend support to raw cids (as opposed to adding multihash support) mostly because I expect it to be less work and it makes sense as we address content either as a car or as a raw blob. I am also more convinced that equivalence claims should use cids as opposed to cid and multihash.

[vasco-santos]

1. We need client to side raw CID instead of carCID with filecoin/offer
2. (we agreed we can do this as follow up) Equivalency claim issued by filecoin pipeline can pick the digest of the received raw CID

[vasco-santos]

Closing by merging https://github.com/w3s-project/w3up/pull/1450#pullrequestreview-2055160233