Gateway conformance

[guanzo]

Fixes #447. Runs the L1 through the gateway conformance tests for specs: trustless-block-gateway, trustless-car-gateway

• Configures lassie to fetch test cids from a localhost kubo node.
• Adds njs module to set the content-disposition header
• All tests pass except for range requests.

A bunch of other commits got pulled in somehow >.<, sorry

[DiegoRBaquero]

Can you please rebase/cherry pick after clean main to clean up other commits ?

[guanzo]

fixed commits