[iOS, Mac] Fix for CursorPosition not updating when typing into Entry control

[SyedAbdulAzeemSF4852]

Note

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It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue. Thank you!

Issue Details

• When typing into Entry control on iOS, the CursorPosition property is not updated.

Root Cause

• OnEditingChanged was updating the text but not the cursor position, causing the virtual view's cursor position to become out of sync with the platform view during typing.

Description of Change

• Introduced a new method UpdateCursorPosition in the ITextInputExtensions class to update the cursor position if it differs from the current value.
• Updated EntryHandler.iOS to call UpdateCursorPosition during the OnEditingChanged event, ensuring the cursor position stays in sync with text changes.

Issues Fixed

Fixes #20911

Validated the behaviour in the following platforms

• Windows
• Android
• iOS
• Mac

Output

Before	After
Before.mov	After.mov

[dotnet-policy-service]

Hey there @@SyedAbdulAzeemSF4852! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[jsuarezruiz]

/azp run MAUI-UITests-public

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Copilot]

Pull Request Overview

This PR ensures the CursorPosition on the Entry control stays in sync when typing on iOS (and Mac Catalyst) by calling a new extension method and validating the behavior with a UI test.

• Added an UpdateCursorPosition extension in ITextInputExtensions to update the cursor when it changes.
• Updated EntryHandler.iOS to invoke UpdateCursorPosition during OnEditingChanged.
• Introduced a HostApp page and a shared UI test (Issue20911) to verify that typing into an Entry updates its cursor position.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/Core/src/Handlers/Entry/EntryHandler.iOS.cs	Invoke UpdateCursorPosition after updating text in OnEditingChanged
src/Core/src/Core/Extensions/ITextInputExtensions.cs	Add UpdateCursorPosition extension method to sync cursor position
src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue20911.cs	Add UI test to enter text and verify the cursor position
src/Controls/tests/TestCases.HostApp/Issues/Issue20911.cs	Create HostApp page with an Entry, status Label, and validation Button

Comments suppressed due to low confidence (2)

src/Controls/tests/TestCases.HostApp/Issues/Issue20911.cs:7

• [nitpick] The variable name cursorPositonStatusLabel has a typo. Consider renaming it to cursorPositionStatusLabel for consistency and clarity.

	Label cursorPositonStatusLabel;

src/Core/src/Core/Extensions/ITextInputExtensions.cs:45

• Consider adding unit tests for UpdateCursorPosition to verify that it correctly updates the CursorPosition when it differs and does nothing when positions are equal.

		internal static void UpdateCursorPosition(this ITextInput textInput, int cursorPosition)