Add namespaces to nf-lang

[bentsherman]

This PR formalizes the concept of "namespaces" in nf-lang to align with the current docs. This allows namespaces to be treated separately in the language server

Also:

• Document log namespace
• Improve related channel docs

[netlify[bot]]

✅ Deploy Preview for nextflow-docs-staging ready!

Name	Link
🔨 Latest commit	790c537bb9e0cd3394442d8408969da71d9b6fcb
🔍 Latest deploy log	https://app.netlify.com/projects/nextflow-docs-staging/deploys/685dca89f2958f00082c7d42
😎 Deploy Preview	https://deploy-preview-6176--nextflow-docs-staging.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.