fix(chrome,loaders): ferry props to view component transient props

[jzempel]

Description

During the styled-components transient naming work, a few props got missed. This PR ensures the following are properly ferried to the underlying view components:

• <Header.ItemWrapper isRound={...} maxX={...} maxY={...}>
• <Dots size={...}>
• <Spinner size={...}>

Detail

Also cleans up Storybook VARIABLES context args that were leaking into rendered styled components.

Checklist

• 👌 design updates will be Garden Designer approved (add the designer as a reviewer)
• 🌐 demo is up-to-date (npm start)
• ⬅️ renders as expected with reversed (RTL) direction
• ⚫ renders as expected in dark mode
• 🤘 renders as expected with Bedrock CSS (?bedrock)
• 💂‍♂️ includes new unit tests. Maintain existing coverage (always >= 96%)
• ♿ tested for WCAG 2.1 AA accessibility compliance
• 📝 tested in Chrome, Firefox, Safari, and Edge