refactor: switch to DAG-CBOR

[lidel]

This PR aims to close #85 and switch b-tree away from expensive JSON stored in Data field of dag-pb and deprecated object RPC API.

TLDR: ~30% DAG size reduction

DAG-PB was 399424 bytes (~400MiB)
DAG-CBOR is 281089143 bytes (~281MiB)

👉 this means ~30% reduction 👌

TODO

• switch from ipfs.object.get to ipfs.block.get
• switch from expensive ipfs.object.put to CAR writer
  • create a CAR with entire b-tree
  • mark final root node as the CAR root
• remove use of DAG-PB and JSON serialized as string
• create DAG-CBOR nodes
  • use CID CBOR tag in links so b-tree can be traversed by generic IPLD libraries and ipfs dag stat in Kubo
  • remove string fields that indicate leaf nodes, use presence of data and links to reason about node type (storage savings)
• bump aegir and switch to ESM
• switch from legacy JS libs to modern https://github.com/multiformats/js-multiformats/
• regenerate dataset and confirm node example/lookup.js 9.9.9.9 returns same result
• detect when ipfs is not CoreAPI instance, but a string, and if it is a valid gateway URL, use it for fetching raw blocks as application/vnd.ipld.raw
• update source dataset and regenerate b-tree, so users not only get storage savings thanks to DAG-CBOR, but also get updated GeoIP database
• cleanup add retry if gateway timeouts
• solve issue with ip dependency requiring native node module

Tests

• fix / update npm test
  -[ ] TBD - maybe we should only support gateways?
  • confirm it works with ipfs.block.get from Kubo
  • confirm it works with ipfs.block.get from JS-IPFS
• confirm it works w
  • https://github.com/ipfs/public-gateway-checker (refactor to use gateway)
  • https://github.com/ipfs/ipfs-webui (refactor to use availableGatewayUrl and pass it similar to how we do it on explore page)

[lidel]

I'm merging this to unblock @whizzzkid to clean up remaining items before we can release:

1. remove dependency on os by doing the build step
2. fix npm test in retry PR

When we have that, I'll regenerate dataset and make the release.