Support Badge in the BottomCommandingContoller demo page

[joannaquu]

Platforms Impacted

• iOS
• macOS

Description of changes

Binary change:

File	Before	After	Delta
libFluentUI.a	28,869,912 bytes	28,927,608 bytes	57,696 bytes

Added new item in BottomCommandingContoller demo page that supports a Badge. To do so, CommandingItem was updated to have a new convenience init that takes in an optional badge. This badge is then provided to TableViewCell's customAccessoryView. Although BadgeView is a UIView, using badge directly with customAccessoryView did not work so the work around was to add it to a UIStackView first.

Verification

Before	Light	Dark

Pull request checklist

This PR has considered:

• Light and Dark appearances
• iOS supported versions (all major versions greater than or equal current target deployment version)
• VoiceOver and Keyboard Accessibility
• Internationalization and Right to Left layouts
• Different resolutions (1x, 2x, 3x)
• Size classes and window sizes (iPhone vs iPad, notched devices, multitasking, different window sizes, etc)
• iPad Pointer interaction
• SwiftUI consumption (validation or new demo scenarios needed)
• Objective-C exposure (provide it only if needed)

Microsoft Reviewers: Open in CodeFlow