docs(ui5-avatar): update Avatar component and documentation

[plamenivanov91]

Changes

Documentation Update

• Updated Avatar badge slot JSDoc to recommend (not require) interactive mode
• Added note: "Badges are recommended on interactive avatars for better UX and accessibility"
• Maintains backwards compatibility - badges work on non-interactive avatars as fallback

Sample Updates

• WithBadge sample: Updated all avatars to use mode="Interactive"
• AvatarBadge samples: Updated Basic and ValueStates samples to use mode="Interactive"
• Interactive sample: Uses mode="Interactive" API (deprecated interactive attr noted)

New Variant Sample

• Created comprehensive "Variants" sample showcasing all Avatar use cases:
  • Non-interactive avatars (decorative)
  • Interactive avatars
  • Interactive avatars with badges (recommended)
  • Interactive avatars with popup menus
  • Decorative avatars (hidden from screen readers)
• Includes accessibility annotations for each variant
• Updated Avatar.mdx to include new Variants section after "With Badge"

Related Issue

Addresses BLI: [ui5-avatar] Samples update - reflects updated screen reader annotations and design specifications

Notes

• All changes follow Conventional Commits specification
• No breaking changes - fully backwards compatible
• Samples now properly demonstrate recommended usage patterns

[ui5-webcomponents-bot]

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