feat: enable gateway-conformance tests

similar to https://github.com/ipfs/bifrost-gateway/blob/70f10e7b9688cd504f881d57ff3fa71215813e16/.github/workflows/gateway-conformance.yml

### Currently passing tests on https://github.com/ipfs/helia-http-gateway/pull/57 (last updated 2023-12-04):

`subdomain-ipns-gateway`

```
PASS: TestMetadata (0.00s)
PASS: TestGatewaySubdomainAndIPNS/request_for_%7BCIDv1-libp2p-key%7D.ipns.%7Bgateway%7D_returns_expected_payload_%28direct_HTTP%29/Status_code (0.00s)
PASS: TestGatewaySubdomainAndIPNS/request_for_%7BCIDv1-libp2p-key%7D.ipns.%7Bgateway%7D_returns_expected_payload_%28HTTP_proxy%29/Status_code (0.00s)
PASS: TestGatewaySubdomainAndIPNS/request_for_%7BCIDv1-libp2p-key%7D.ipns.%7Bgateway%7D_returns_expected_payload_%28direct_HTTP%29#01/Status_code (0.00s)
PASS: TestGatewaySubdomainAndIPNS/request_for_%7BCIDv1-libp2p-key%7D.ipns.%7Bgateway%7D_returns_expected_payload_%28HTTP_proxy%29#01/Status_code (0.00s)
PASS: TestGatewaySubdomainAndIPNS/request_for_%7BCIDv1-libp2p-key%7D.ipns.%7Bgateway%7D_returns_expected_payload_%28direct_HTTP%29#02/Status_code (0.00s)
PASS: TestGatewaySubdomainAndIPNS/request_for_%7BCIDv1-libp2p-key%7D.ipns.%7Bgateway%7D_returns_expected_payload_%28HTTP_proxy%29#02/Status_code (0.00s)
PASS: TestGatewaySubdomainAndIPNS/request_for_%7BCIDv1-libp2p-key%7D.ipns.%7Bgateway%7D_returns_expected_payload_%28direct_HTTP%29#03/Status_code (0.00s)
PASS: TestGatewaySubdomainAndIPNS/request_for_%7BCIDv1-libp2p-key%7D.ipns.%7Bgateway%7D_returns_expected_payload_%28HTTP_proxy%29#03/Status_code (0.00s)
```

`subdomain-ipfs-gateway`

```
PASS: TestMetadata (0.00s)
PASS: TestGatewaySubdomains/request_for_%7BCID%7D.ipfs.example.com_should_return_expected_payload_%28direct_HTTP%29/Status_code (0.00s)
PASS: TestGatewaySubdomains/request_for_%7BCID%7D.ipfs.example.com_should_return_expected_payload_%28direct_HTTP%29/Body (0.00s)
PASS: TestGatewaySubdomains/request_for_%7BCID%7D.ipfs.example.com_should_return_expected_payload_%28direct_HTTP%29 (0.99s)
PASS: TestGatewaySubdomains/request_for_%7BCID%7D.ipfs.example.com_should_return_expected_payload_%28HTTP_proxy%29/Status_code (0.00s)
PASS: TestGatewaySubdomains/valid_file_and_subdirectory_paths_in_directory_listing_at_%7Bcid%7D.ipfs.example.com_%28direct_HTTP%29/Status_code (0.00s)
PASS: TestGatewaySubdomains/valid_file_and_subdirectory_paths_in_directory_listing_at_%7Bcid%7D.ipfs.example.com_%28HTTP_proxy%29/Status_code (0.00s)
PASS: TestGatewaySubdomains/request_for_%7BCID%7D.ipfs.example.com_should_return_expected_payload_%28direct_HTTP%29#01/Status_code (0.00s)
PASS: TestGatewaySubdomains/request_for_%7BCID%7D.ipfs.example.com_should_return_expected_payload_%28direct_HTTP%29#01/Body (0.00s)
PASS: TestGatewaySubdomains/request_for_%7BCID%7D.ipfs.example.com_should_return_expected_payload_%28direct_HTTP%29#01 (0.00s)
PASS: TestGatewaySubdomains/request_for_%7BCID%7D.ipfs.example.com_should_return_expected_payload_%28HTTP_proxy%29#01/Status_code (0.00s)
PASS: TestGatewaySubdomains/valid_file_and_subdirectory_paths_in_directory_listing_at_%7Bcid%7D.ipfs.example.com_%28direct_HTTP%29#01/Status_code (0.00s)
PASS: TestGatewaySubdomains/valid_file_and_subdirectory_paths_in_directory_listing_at_%7Bcid%7D.ipfs.example.com_%28HTTP_proxy%29#01/Status_code (0.00s)
```

```[tasklist]
### Tasks
- [x] Figure out how to load fixtures (need to do via new api-endpoint if we're using in-memory block/data stores)
- [ ] Address failure for `http://localhost:8090/ipns/?uri=ipns%3A%2F%2Fdnslink-subdomain-gw-test.example.org` requests
- [ ] fix `http://localhost:8090/ipns/dnslink-subdomain-gw-test.example.org/wiki`
- [ ] fix `http://k51qzi5uqu5dk3v4rmjber23h16xnr23bsggmqqil9z2gduiis5se8dht36dam.ipns.localhost:8090
- [ ] fix `http://localhost:8090/ipns/QmVujd5Vb7moysJj8itnGufN7MEtPRCNHkKpNuA4onsRa3`
- [ ] fix IPNS resolution using IPNS fixtures loaded in kubo
```