feat: updates icon component and prop types for cross-package consistency

[geotrev]

Description

Updates multiple packages so their icon prop types are consistent with other packages. Also updates several component type signatures as well.

See migration.md for full changelog.

Detail

There are several icon components still using div styled component that nest an svg icon inside them. I didn't touch these as they're still spreading props and setting their ref to the styled div, not the svg directly.

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 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

[coveralls]

coverage: 96.022% (-0.001%) from 96.023%
when pulling 84dd45f on george/icon-type-update
into d5fa1dc on next.

[jzempel]

@geotrev this is a good start and good for what this PR is. But I think we're looking for more out of the sequence task before it's considered complete for v9. Let's sync up on the internal doc comments.

[jzempel]

Now I think we're missing Span icons. Maybe others. Be sure to scour for styled component usage with cloneElement. Fwiw, I think we should expose a utility StyledIcon (or something similar) base class. But that's TBD.