Support full-width looping videos in articles

[simonbyford]

What does this change?

Does two things:

1. sets the aspect ratio of the container for looping videos in articles by passing in containerAspectRatio. This follows on from Set aspect ratio of containers to prevent CLS #15029
2. adds support for full-width self-hosted videos. Looping videos in articles should display at full-width. Looping videos on fronts should continue to display in a fixed-size box with letterboxing (i.e. not full-width)

Why?

Editorial have requested it. There is a precedent because this is how images currently behave in articles.

Screenshots

Before	After

[github-actions]

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From guardian/actions-riff-raff.

[github-actions]

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[paperboyo]

🎁🎄 Yay!

Just a useless naming thought: even though fronts were where the player was born, they are a special case (letter-boxed?), while the behaviour in articles after your PR is what’s normal and expected. Once we finally have different weightings (roles) there, it may not exactly be “full-width” either.

If it’s easier as is, I haven’t wrote this comment.

Merry Xmas!

[simonbyford]

🎁🎄 Yay!

Just a useless naming thought: even though fronts were where the player was born, they are a special case (letter-boxed?), while the behaviour in articles after your PR is what’s normal and expected. Once we finally have different weightings (roles) there, it may not exactly be “full-width” either.

If it’s easier as is, I haven’t wrote this comment.

Merry Xmas!

Thanks @paperboyo! I like your suggestion and I've made the change here: 0f2b3b0

letterboxed is false in the default case, but true for fronts.