feat: Switch to OpenSans (backport #15958)

[mergify]

GitHub Issue (If applicable): closes #3954, closes #17381

PR Type

What kind of change does this PR introduce?

What is the current behavior?

What is the new behavior?

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):

---

This is an automatic backport of pull request #15958 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of e9a3ded has failed:

On branch mergify/bp/release/stable/5.3/pr-15958
Your branch is ahead of 'origin/release/stable/5.3' by 8 commits.
  (use "git push" to publish your local commits)

You are currently cherry-picking commit e9a3ded327.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   src/SamplesApp/Directory.Build.targets

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   src/SamplesApp/SamplesApp.Shared/App.xaml.cs

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[unodevops]

🤖 Your WebAssembly Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-17451/index.html

[unodevops]

🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-17451/index.html