[Theme][macOS] Adding hover tokens

[DanielMorM]

Platforms Impacted

• iOS
• visionOS
• macOS

Description of changes

Adds hover state color tokens for macOS backgrounds. These tokens are marked as unavailable on iOS, visionOS, and macCatalyst since hover interactions are specific to pointer-based platforms.

FluentTheme+Tokens.swift

• Added 6 new ColorToken enum cases for hover states:
  • background1Hover, background2Hover, background3Hover, background5Hover
  • brandBackground1Hover, brandBackground2Hover
  • All new hover tokens are marked @available(iOS, unavailable), @available(visionOS, unavailable), @available(macCatalyst, unavailable)

FluentTheme+macOS.swift

• Added color implementations for the new hover tokens with light/dark mode values
• Updated brandBackground2 and brandBackground2Pressed to include dark mode values (previously only had light mode)

TestAliasColorTokensViewController.swift (macOS Demo)

• Added new hover tokens to the demo sections for neutral backgrounds and brand backgrounds
• Added display names and text color handling for the new tokens

Binary change

(how is our binary size impacted -- see https://github.com/microsoft/fluentui-apple/wiki/Size-Comparison)

Verification

• Manual testing via the macOS demo app which now displays all new hover tokens
• Visual verification of hover token colors in light and dark mode

Visual Verification

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