Expose TextBox/NumberBox/AutoSuggestBox clear button to Voice Access

[Harini Malothu (HariniMalothu17)]

Summary

Fixes the Voice Access issue where the TextBox / NumberBox / AutoSuggestBox inline clear (x) button could not be targeted by a number tag.

When the inline clear button is shown (for example a NumberBox with SpinButtonPlacementMode="Inline"), the button clears the entered text. It is a real named Button that already receives a localized UIA name ("Delete"). However, the template explicitly set AutomationProperties.AccessibilityView="Raw" on that DeleteButton, which excludes the element from the UIA Content view. Voice Access "Show numbers" only tags elements in the Content view, so the clear button never received a number tag and could not be targeted hands-free.

Repro (from #7996)

1. Open the Gallery > NumberBox.
2. Change SpinButton placement to Inline.
3. Click in the "Enter an integer" number box and type a value.
4. Turn on Voice Access and say "Show numbers".
5. Observe that numbers appear on the input area and the up/down arrows, but not on the clear (x) button.

What changed

Removed the explicit AutomationProperties.AccessibilityView="Raw" from the DeleteButton in every affected template, reverting it to its default Content accessibility view. Because the button remains Visibility="Collapsed" (only shown in the ButtonVisible visual state) and keeps IsTabStop="False", it is exposed to Voice Access only while it is actually visible, and keyboard tab order is unchanged.

• controls/dev/CommonStyles/TextBox_themeresources.xaml — removed AccessibilityView="Raw" from the DeleteButton in the default TextBox template.
• controls/dev/CommonStyles/TextBox_themeresources_perf2026.xaml — same change in the perf2026 TextBox template copy.
• controls/dev/NumberBox/NumberBox.xaml — removed AccessibilityView="Raw" from the DeleteButton in the inner NumberBox TextBox style.
• controls/dev/NumberBox/NumberBox_perf2026.xaml — same change in the perf2026 NumberBox template copy.
• controls/dev/AutoSuggestBox/AutoSuggestBox_themeresources.xaml — removed AccessibilityView="Raw" from the DeleteButton.
• controls/dev/AutoSuggestBox/AutoSuggestBox_themeresources_perf2026.xaml — same change in the perf2026 AutoSuggestBox template copy.

Tests

• controls/dev/NumberBox/InteractionTests/NumberBoxTests.cs — added VerifyClearButtonIsAccessible: switches NumberBox to inline mode, enters a value so the clear button is visible, and verifies the "Delete" button is exposed to UIA (found in the inner TextBox subtree), distinct from the Increase/Decrease spin buttons, then invokes it and checks the text is cleared.
• controls/dev/CommonStyles/InteractionTests/CommonStylesTests.cs — added TextBoxClearButtonIsAccessibleTest: focuses a TextBox so the clear button is visible and verifies the "Delete" button is exposed to UIA and clears the text when invoked.
• controls/dev/CommonStyles/TestUI/TextControlsPage.xaml — named the test TextBox so the new test can find it.

Fixes #7996

[Harini Malothu (HariniMalothu17)]

/azp run

[azure-pipelines]

Azure Pipelines:
1 pipeline(s) were filtered out due to trigger conditions.

[Harshit (harshit7962)]

/azp run

[azure-pipelines]

Azure Pipelines:
1 pipeline(s) were filtered out due to trigger conditions.

[Harini Malothu (HariniMalothu17)]

Superseded by #11656, which contains the identical commit (c9f6b76) raised from a branch on microsoft/microsoft-ui-xaml so PR validation runs (fork PRs don't trigger the pipeline). Closing this one.