Test: Add Sample Test for Expander header bindings

[ajpinedam]

GitHub Issue (If applicable):

related https://github.com/unoplatform/uno/issues/17312

PR Type

What kind of change does this PR introduce?

• Other... Please describe:

What is the current behavior?

What is the new behavior?

This PR adds a sample to the Sample App to reproduce the error reported on https://github.com/unoplatform/uno/issues/17312. This will help validate whether the Fix being worked on in PR https://github.com/unoplatform/uno/pull/17645 does indeed fix the problem.

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.
• [x] Contains NO breaking changes
• [x] Associated with an issue (GitHub or internal) and uses the automatic close keywords.
• [x] Commits must be following the Conventional Commits specification.

Other information

Internal Issue (If applicable):

[unodevops]

🤖 Your WebAssembly Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-17895/index.html

[unodevops]

🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-17895/index.html

[unodevops]

🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-17895/index.html

[unodevops]

🤖 Your WebAssembly Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-17895/index.html

[ajpinedam]

/azp run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 2 pipeline(s).

[unodevops]

🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-17895/index.html

[ajpinedam]

/azp run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 2 pipeline(s).

[unodevops]

🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-17895/index.html

[unodevops]

⚠️⚠️ The build 154888 has failed on Uno.UI - CI.

[jeromelaban]

@ajpinedam almost there: https://dev.azure.com/uno-platform/Uno%20Platform/_build/results?buildId=154888&view=logs&j=e2ff3c96-067d-5a43-7f8d-fe20c91c0387&t=3a41b04b-7a6e-578b-fc13-73a18e595201&l=151

[unodevops]

🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-17895/index.html

[unodevops]

🤖 Your WebAssembly Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-17895/index.html

[unodevops]

⚠️⚠️ The build 155520 has failed on Uno.UI - CI.

[unodevops]

🤖 Your WebAssembly Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-17895/index.html

[unodevops]

🤖 Your WebAssembly Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-17895/index.html

[unodevops]

⚠️⚠️ The build 155914 has failed on Uno.UI - CI.