feat: helia-http-gateway as a service worker (phase 2)

This issue is intended to pull out work mentioned in https://github.com/ipfs/helia/issues/275 and required for [IPFS dApps working group](https://lu.ma/ipfs-dapps) into it's own epic:

```[tasklist]
### Tasks
- [x] Create helia-http-gateway-sw: a service worker version of all the helia-http-gateway logic
- [ ] Create helia-service-worker browser gateway that can work with probelab's tiros
```

Some important links to previous discussions:

- https://github.com/ipfs/helia/issues/275#issuecomment-1747965736
-

Start by reading the existing helia-http-gateway-sw implementation, then review helia issue 275 and the linked discussion comments. Determine the remaining scope for a helia-service-worker browser gateway that works with probelab's tiros. Done means the unchecked task is implemented and its compatibility with tiros is demonstrated.

Written by the indexing model from the issue text.