Migrate components to TS: AvatarIcon

[georgewrmarshall]

Description

Migrate AvatarIcon component in ui/components/component-library to TypeScript

Dependencies

• Create TS version of Box component in component-library #19239

Technical Details

• Convert Objects in SNAKE_CASE to enums in PascalCase (name and keys)
• Ensure enums use singular not plural e.g. Size not Sizes
• Update file name from component-name.contants.js to component-name.types.ts and add types
• Update file name from component-name.js to component-name.tsx and add types
• Update file name from component-name.test.js to component-name.test.tsx
• Update file name from component-name.stories.js to component-name.stories.tsx
• Update all instances of component objects to enums
• Update all documentation

Acceptance Criteria

• Component has been converted to TypeScript
• Stories, documentation and tests have been updated inside of the component-name folder
• Before/After screen cast of component stories in storybook to show no visual regression after migration

Difficulty: Intermediate

Good first issue for: External contributors who are familiar with TypeScript and want to contribute to improving the stability of the extension

[georgewrmarshall]

Removing good-first-issue label until we close the Box dependency #19239