[Refactor] Remaining Storybook 6 Upgrade Items

[Coteh]

Leftover stuff from #996.

• Consider switching addons-knobs to Storybook Controls
• Convert story items to use Storybook Args (source)
• Ensure everything else from Migrations guide is checked off
• Consider adding MDX documentation to stories (should probably make this a separate issue that can be dealt with later, since it's more of a nice-to-have) (source)
• Upgrade to latest minor release