feat: WinUI `ContentDialog`

[MartinZikmund]

GitHub Issue (If applicable): closes #19128

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What kind of change does this PR introduce?

What is the current behavior?

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PR Checklist

Please check if your PR fulfills the following requirements:

• [ ] Docs have been added/updated which fit documentation template (for bug fixes / features)
• [ ] Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• [ ] Validated PR Screenshots Compare Test Run results.
• [ ] Contains NO breaking changes
• [ ] Associated with an issue (GitHub or internal) and uses the automatic close keywords.
• [ ] Commits must be following the Conventional Commits specification.

Other information

Internal Issue (If applicable):

[unodevops]

🤖 Your docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-14770/index.html

[github-actions[bot]]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or it will be closed in 10 days.

[unodevops]

🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-14770/docs/index.html

[github-actions[bot]]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or it will be closed in 10 days.