feat!: IPNS routing based on IPIP-351 or IPIP-379

[hacdias]

Towards #151, allows resolving IPNS without KUBO_RPC_URL being set

• adds IPNS_RECORD_GATEWAY_URL
• uses either legacy KUBO_RPC_URL or modern IPNS_RECORD_GATEWAY_URL or PROXY_GATEWAY_URL with support for application/vnd.ipfs.ipns-record responses

Not sure what to do regarding testing here. We haven't had testing before and it seems a bit complicated to automate. I tried locally with both Kubo gateway and Routing V1 and it worked 🥳

[lidel]

Thank you for cleaning this up.
Perhaps we could clean up bit more – see DefaultKuboRPC comment inline.

We haven't had testing before and it seems a bit complicated to automate. I tried locally with both Kubo gateway and Routing V1 and it worked partying_face

I think this is already handled by gateway-conformance, it runs in CI and since #181 we also test IPNS content paths, including raw ipns-record fixtures imported in .github/workflows/gateway-conformance.yml.

So no need for additional testing imo. 👍

[lidel]

@hacdias thanks! two asks inline 🙏

[hacdias]

Ping @lidel

[lidel]

lgtm, pushed cosmetic fix for better ux and rebased

Note: this should be safe to merge, as it does not impact Rhea deployments which all have KUBO_RPC_URL set:

https://github.com/ipfs/bifrost-gateway/blob/04eb5db2f270271b0675de1a90708d2d173dd780/Dockerfile#L34