[Mac] [Focus Zone] Restore broken direction = none functionality

[nakambo]

Platforms Impacted

• [ ] iOS
• [x] macOS
• [ ] win32 (Office)
• [ ] windows
• [ ] android

Description of changes

In a previous change, I incorrectly refactored some functionality that caused focus zone to respond to arrow keys even when direction was set to none. This change restores direction = none functionality.

Verification

Manual testing:

• Disabled focus zone: tab works normally (as if no focus zone is present), arrow keys beep
• Arrow keys on direction = none zone: tab works like focus zone (move to outside the zone), arrow keys beep
• Arrow keys on direction = horizontal zone: tab works like focus zone (move to outside the zone), vertical arrow keys beep, horizontal arrow keys move in zone
• Arrow keys on direction = vertical zone: tab works like focus zone (move to outside the zone), horizontal arrow keys beep, vertical arrow keys move in zone
• Arrow keys on direction = bidirectional zone: tab works like focus zone (move to outside the zone), arrow keys move in zone

Pull request checklist

This PR has considered (when applicable):

• [ ] Automated Tests
• [ ] Documentation and examples
• [x] Keyboard Accessibility
• [x] Voiceover: n/a
• [ ] Internationalization and Right-to-left Layouts

[PPatBoyd]

[non-blocking] relevant but not for this PR: FocusZone.types.ts doesn't note the default FocusZoneDirection which probably should be Direction=None but defaults to Bidirectional due to how the native enum is defined.

which would be a breaking change and need to be minded for uptake by consumers to adjust accordingly... woo...