[Testing] Fix flaky UITests failing sometimes 3 - Alternative

[jsuarezruiz]

Description of Change

Tests:

• VerifyInitialEntryReturnTypeChange. Capture depends on a blinking Entry cursor. Sometimes it happens, sometimes it doesn't. Fixed test, cursor is not captured in the image.

Alternative to #27277

• Added a mapper to just make the caret transparent by default on the UITests.
• Added a Behavior that can add the caret back if necessary in some UITests.

Copilot reviewed 6 out of 8 changed files in this pull request and generated no comments.

Files not reviewed (2)

• src/Controls/tests/TestCases.HostApp/Platforms/MacCatalyst/IsCursorVisibleBehavior.cs: Evaluated as low risk
• src/Controls/tests/TestCases.HostApp/Platforms/Windows/IsCursorVisibleBehavior.cs: Evaluated as low risk

Comments suppressed due to low confidence (1)

src/Controls/tests/TestCases.HostApp/Behaviors/IsCursorVisibleBehavior.cs:6

• Ensure that the IsCursorVisible property is covered by tests to verify its behavior.

BindableProperty.Create(nameof(IsCursorVisible), typeof(bool), typeof(IsCursorVisibleBehavior));