chore(Storybook): Hide controls for className and style attributes

[VincentSmedinga]

Describe the pull request

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What

Prevents controls for the className and style attributes from showing up in Storybook.

Why

• They appear when we set values for them to improve our examples, but people needn’t know and have no use for them themselves.
• Specifying this in preview.tsx addresses this once and for all.
• It’s still possible to override this setting if we want to show one of these attributes for a specific component or story.

How

n/a

Checklist

Before submitting your pull request, please ensure you have done the following. Check each checkmark if you have done so or if it wasn't necessary:

• Add or update unit tests
• Add or update documentation
• Add or update stories
• Add or update exports in index.* files
• Start the PR title with a Conventional Commit prefix, as explained here.

Additional notes

• n/a