Cleanup TestProgressState

[Youssef1313]

Closes #48369

[Copilot]

Pull Request Overview

This PR refactors the TestProgressState class to improve code clarity and maintainability by consolidating duplicate logic and removing unused properties. The main focus is on cleaning up the test result reporting mechanism.

Key changes:

• Refactored three similar test reporting methods into a single generic method
• Removed unused properties (ExitCode, FlakyTests) and comments
• Added comprehensive test coverage for the TestProgressState class

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
test/dotnet.Tests/CommandTests/Test/TestProgressStateTests.cs	New comprehensive test file covering all scenarios for TestProgressState functionality
src/Cli/dotnet/Commands/Test/TestApplicationEventHandlers.cs	Removed outdated TODO comment about handling duplicate test results
src/Cli/dotnet/Commands/Test/Terminal/TestProgressState.cs	Major refactoring - consolidated duplicate logic into ReportGenericTestResult method and removed unused properties
src/Cli/dotnet/Commands/Test/Terminal/TerminalTestReporter.cs	Removed unused flaky test tracking logic and ExitCode property usage

Comments suppressed due to low confidence (1)

test/dotnet.Tests/CommandTests/Test/TestProgressStateTests.cs:46

• The test is missing FluentAssertions using statement. The Should() extension method requires 'using FluentAssertions;' to be added to the imports.

                state.SkippedTests.Should().Be(1);