Set up takedown page UI

[junyuanxue]

What does this change?

A scaffold of takedown page UI, with some placeholder copy for each step.

• Page /takedown is set up with React, and uses @guardian/stand components. I've added some default theme overrides to support the dark background of the Grid.
• I've opted for custom styling localised to elements using @emotion/react, in line with @guardian/stand style overrides, so we don't have the problem of having multiple ways of styling within one component. (And generally, I think we should move away from CSS stylesheets and towards more localised styles and leaning on thematic abstraction rather than abstraction by custom classnames).
• Some base sketch and UI of hard-coded takedown steps - these will be filled out in upstack PRs.
• Page is behind a feature switch through kahuna.conf for now.

How should a reviewer test this change?

• In your local ~/.grid/kahuna.conf, add image.takedown.enabled=true, run the Grid using --use-TEST so you have permissions
• Go to an image page, and append '/takedown' at the end of the url. You'll need the 'delete_crops_or_usages' permission to access it

Tested? Documented?

• locally by committer
• locally by Guardian reviewer
• on the Guardian's TEST environment
• relevant documentation added or amended (if needed)

---

• To see the specific tasks where the Asana app for GitHub is being used, see below:
  • https://app.asana.com/0/0/1218365541511350

[github-actions]

Deploy build 15277 of media-service::grid::all to TEST

All deployment options

• Deploy build 15277 of media-service::grid::all to TEST
• Deploy parts of build 15277 to TEST by previewing it first
• What's on TEST right now?

---

From guardian/actions-riff-raff.

[lindseydew]

LGTM, nice work ✨

[lindseydew]

I like this flow.

I'm wondering a bit about the status updates.

We can get to it nearer the time, but I think it would be good to use the data from the API to say whether or not it can be clicked

[junyuanxue]

Yes, this will be based on data-fetching results inside a context provider: https://github.com/guardian/grid/pull/4935/changes#diff-32c0a79d82d1fd5f0c4e9c8e458d55c64537f51cc7144f77acbaaa3b6daeccb9

[gu-prout]

Seen on auth, metadata-editor, cropper, media-api, kahuna (merged by @junyuanxue 10 minutes and 40 seconds ago) Please check your changes!

[gu-prout]

Seen on collections, leases, usage (merged by @junyuanxue 10 minutes and 51 seconds ago) Please check your changes!

[gu-prout]

Seen on image-loader, thrall (merged by @junyuanxue 11 minutes ago) Please check your changes!