Consider Passing Format And Dark Mode Into Interactive Elements And Atoms

There are two ways of introducing interactive content into non-interactive articles:

1. Interactive atoms
2. Interactive elements

For 1) we already pass information about whether dark mode is supported as of #10298. There has been a suggestion from the Visuals team that it might be useful to also do something like this for 2). An additional suggestion was that we may want to pass `ArticleFormat` into both 1) and 2), so other variations of article design (like the backgrounds on analysis[^1] and comment[^2] pieces) could be handled.

[^1]: https://www.theguardian.com/tone/analysis
[^2]: https://www.theguardian.com/tone/comment