Test consistency between /routing/v1 and /cid

[lidel]

Lookout seems to already test /cid endpoint, but is not checking /routing/v1/providers – it would detect the problem we had on 2023-06-15.

Based on today's post-portem call, we need tests:

• request Accept: application/json
• run again, request streaming Accept: application/x-ndjson (https://specs.ipfs.tech/ipips/ipip-0410/)
• basic smoke test: confirm the first top result is the same for both + the same as results from /cid

cc @masih