Add ShowcaseLayout for apps

[sunnyclimber456]

What does this change?

This change adapts the ShowcaseLayout for apps. Generally, apps layouts differ from web in the following ways:

• Apps do not show the web header and footer. Apps show their own footer
• Apps do not show web ads. Apps show their own ads
• Apps do not show the web onwards container
• Apps do not render the "body end slot"
• Apps do not show the most viewed in the footer

showcaselayout.mp4

Closes #8997

[github-actions]

Size Change: 0 B 🆕

Total Size: 0 B

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[sunnyclimber456]

https://github.com/guardian/mobile-apps-api/pull/2713 adds support to MAPI for articles which use the apps ShowcaseLayout.

[ioannakok]

Is merchandising-high ad slot the same in DCAR?

PS. I really wanted to comment on the unchanged line but we'll have to wait till this one's done!

[sunnyclimber456]

Is merchandising-high ad slot the same in DCAR?

PS. I really wanted to comment on the unchanged line but we'll have to wait till this one's done!

@ioannakok I don't think so- I think apps articles don't include any of the web ad slots. We only render that slot in ShowcaseLayout if renderAds === true. The condition for renderAds is renderingTarget === 'Web' && canRenderAds(article);, so merchandising-high wouldn't render for ads.