Description

This PR updates the ExternalLink component to use CSS-in-JS similar to how newer components do like the AnglePickerControl and Text. This also maintains the existing classname on the Icon even though it isn't being used by the component itself, it allows the Icon to still be targeted by consumers, making this a non-breaking change.

How has this been tested?

I've run storybook and observed that there are new visual differences in before and after.

Screenshots

Before:

After:

Types of changes

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.