[#44836] Re-think naming of "premium feature" vs "enterprise feature"

* fix anchors
* harmonize Cloud edition to Enterprise cloud
* harmonize Enterprise Edition to Enterprise on-premises
* fix anchors in story book & core
* fix renamed video url
* fix renamed image url
* task(docs): fix anchor links
* task(docs): one more 2FA headline change

https://community.openproject.org/work_packages/44836