Extend httperror analyzer to more functions (#16186)

**What type of PR is this?**

Tooling

**What does this PR do? Why is it needed?**

Renames `httperror` analyzer to `httpwriter` and extends it to the
following functions:
- `WriteError`
- `WriteJson`
- `WriteSsz`

_**NOTE: The PR is currently red because the fix in
https://github.com/OffchainLabs/prysm/pull/16175 must be merged first**_

**Acknowledgements**

- [x] I have read
[CONTRIBUTING.md](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md).
- [x] I have included a uniquely named [changelog fragment
file](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md#maintaining-changelogmd).
- [x] I have added a description with sufficient context for reviewers
to understand this PR.
- [x] I have tested that my changes work as expected and I added a
testing plan to the PR description (if applicable).

network/httputil/writer.go

@@ -43,6 +43,7 @@ func WriteJson(w http.ResponseWriter, v any) {
 func WriteSsz(w http.ResponseWriter, respSsz []byte) {
 	w.Header().Set("Content-Length", strconv.Itoa(len(respSsz)))
 	w.Header().Set("Content-Type", api.OctetStreamMediaType)
+	w.WriteHeader(http.StatusOK)
 	if _, err := io.Copy(w, io.NopCloser(bytes.NewReader(respSsz))); err != nil {
 		log.WithError(err).Error("Could not write response message")
 	}