Add Storybook preview styles that allow for sticky header/column

[rogermparent]

storybook-sticky-demo.mp4

This PR adds width and height 100% styles to Storybook's preview, allowing for the sticky UI elements recently introduced to be seen in Storybook. This does require viewports to be disabled, but after that the feature can be seen.

[sroy3]

I think there is a way to disable viewports on specific stories. I haven't done it yet, but I think it should be as simple as overriding the default viewport parameter in preview.ts to add disable

[rogermparent]

I think there is a way to disable viewports on specific stories.

That could be useful for a story that specifically targets the sticky UI use case, but since all the stories that are currently there have their own use cases that can benefit from viewports I'm not sure where we'd do so.

[codeclimate]

Code Climate has analyzed commit 2b0ee97 and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (85% is the threshold).

This pull request will bring the total coverage in the repository to 96.9% (0.0% change).

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