Cleanup old stream stuff

/cc @wheresrhys @kaelig @laurent-muchacho @commuterjoy 

- Remove anything stream related from Grumman to avoid confusion!
- Rename article-card classes to article so it doesn't clash with cards
- Bring in template copying from dobi
Good point. It shouldn't. And should be a h1. I think the JS that refers to article-full__link is also using the href (to store data for save-for-later) - so I will change these as a separate PR.