✨ feat(mq-lang): add http_*_json builtins to parse HTTP responses as JSON

[harehare]

Summary

Add http_get_json/http_post_json/http_put_json/http_patch_json/http_delete_json to builtin.mq, composing the existing http() and _json_parse() builtins so callers can fetch a URL and get back a dict/array directly instead of a raw string.

Type of Change

• 🐛 Bug fix
• ✨ New feature
• ♻️ Refactor
• 📝 Documentation
• ⚡ Performance
• ✅ Test
• 📦 Build / dependencies
• 👷 CI

Checklist

• I ran cargo fmt and cargo clippy and addressed any warnings
• I ran just test-all and all tests pass
• I added or updated tests covering this change
• I updated relevant documentation (/docs, crate README.md) if needed
• I added a changelog entry if this is a user-facing change

Additional Context

[codspeed-hq]

Merging this PR will not alter performance

✅ 31 untouched benchmarks

---

_{Comparing feat/http-json-helpers (93aa860) with main (5ee8974)¹}

Footnotes

1. No successful run was found on main (45a59c8) during the generation of this report, so 5ee8974 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩