feat: add test 109

[laurentsenta]

Contributes to #26

[laurentsenta]

@galargh I came up with a new pattern for testing with subdomains:
instead of explicitly calling a function on every test:

gateway-conformance/tests/t0114_gateway_subdomains_test.go

Lines 49 to 56 in 023888a

	with(testGatewayWithManyProtocols(t,
	"request for example.com/ipfs/{CIDv1} redirects to subdomain",
	`
	subdomains should not return payload directly,
	but redirect to URL with proper origin isolation
	`,
	URL("%s/ipfs/%s/", gatewayURL, CIDv1),
	Expect().

unwrapTests takes a bunch of tests relying on a subdomain, and unwrap them; it's more natural when you write the tests. Super easy to implement thanks to Builders being immutable.

It's composable also, so I'm this close 🤏 to moving the loop over multiple gateways into another unwrapper:

	gatewayURLs := []string{
		SubdomainGatewayURL,
		SubdomainLocalhostGatewayURL,
	}

=> unwrapTests(unwrapGateways(tests))

(You'd write the test once for local host gateway, and if subdomain parameter exists and is enabled, we'll clone every test cases)

Not perfect, but a step in a better direction I think, maybe that'll inspire some ideas on your side :)

[laurentsenta]

@galargh that's the fix for the crazy bug I shared yesterday,

• I double-checked: init() is called only once per package as we expected.
• When I renamed fixture.go into zfixture.go, the bug was fixed 🎉
• I realized this had to be a collision between new boxo packages and the old ones.

[galargh]

🤯