Add initial support for Multiple Windows on MacOS

[ne0rrmatrix]

• Bug fix

Description of Change

Add support for more than one window on MacOS. With this PR Media Element will now show multiple windows when you visit the Multi-Window Page on MacOS.

Linked Issues

• Fixes #2249

PR Checklist

• [x] Has a linked Issue, and the Issue has been approved(bug) or Championed (feature/proposal)
• [ ] Has tests (if omitted, state reason in description)
• [x] Has samples (if omitted, state reason in description)
• [x] Rebased on top of main at time of PR
• [x] Changes adhere to coding standard
• [x] Documentation created or updated: https://github.com/MicrosoftDocs/CommunityToolkit/pull/476

Additional information

With this PR MacOS will fully support multiple windows on MacOS when using Media Element. Documentation will need updating to add the changes to Manifest file for MacOS.