Upstream changes
- implement above changes for 3 panel view, add basic tooltip
- make headline elements with feed title lead to originating site while RSS icon elements lead to the feed within tt-rss UI
- fix unfunctional rss icon in grouped-by-feed heading
- use OCI for integration tests
- fix missing include
- switch to template helm ci
- Merge branch 'feature/rssutils-use-feedenclosure' into 'master'
- Use FeedEnclosure throughout RSSUtils.