fix(TextBlock): when measuring, always return text size even if bigger than available size on WASM

[ramezgerges]

GitHub Issue (If applicable): closes https://github.com/unoplatform/kahua-private/issues/289

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):

[unodevops]

🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-20442/docs/index.html

[unodevops]

🤖 Your WebAssembly Skia Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-20442/wasm-skia-net9/index.html

[unodevops]

⚠️⚠️ The build 165971 has failed on Uno.UI - CI.

[jeromelaban]

@ramezgerges some tests are failing https://dev.azure.com/uno-platform/Uno%20Platform/_TestManagement/Runs?runId=3365650&_a=resultSummary&resultId=100702

[Copilot]

Pull Request Overview

This PR ensures that on WASM the TextBlock measurement always reflects its full text size, and adds a UI test to verify overflow behavior.

• Unbounds height (and width when no-wrap) in MeasureOverride for WASM to return actual text size.
• Adds When_Text_Does_Not_Fit test to verify horizontal scrolling when text exceeds bounds.
• Imports Uno.UI.Extensions in tests for helper methods.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/Uno.UI/UI/Xaml/Controls/TextBlock/TextBlock.wasm.cs	Adjust measure logic to unbound height and conditional width for no-wrap
src/Uno.UI.RuntimeTests/Tests/Windows_UI_Xaml_Controls/Given_TextBlock.cs	Added new overflow test and required namespace import

Comments suppressed due to low confidence (1)

src/Uno.UI.RuntimeTests/Tests/Windows_UI_Xaml_Controls/Given_TextBlock.cs:814

• [nitpick] The variable name lv is ambiguous. Consider renaming it to listView to improve readability and clarity.

var lv = new ListView()

[unodevops]

🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-20442/docs/index.html

[unodevops]

🤖 Your WebAssembly Skia Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-20442/wasm-skia-net9/index.html

[unodevops]

⚠️⚠️ The build 166194 has failed on Uno.UI - CI.

[jeromelaban]

@ramezgerges the test is still failing: https://dev.azure.com/uno-platform/Uno%20Platform/_TestManagement/Runs?runId=3368139&_a=resultSummary&resultId=100001