Updatess to tsc tests

[sheetalkamat]

These are first few commits from #1484 that only change tests framework

[Copilot]

Pull Request Overview

This PR updates the TypeScript tests framework to improve test infrastructure and baseline handling. The changes refactor test execution, output processing, and baseline generation to create more consistent and maintainable test results.

Key changes:

• Refactored test system architecture with improved timing and output handling
• Updated baseline files to include additional timing and configuration information
• Enhanced test infrastructure with better clock simulation and file system handling

Reviewed Changes

Copilot reviewed 55 out of 55 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
testdata/baselines/reference/tscWatch/**/*.js	Updated baseline files to include build timing markers and tsconfig references
testdata/baselines/reference/tsc/**/*.js	Updated baseline files with improved output formatting and configuration tracking
internal/vfs/vfstest/vfstest.go	Enhanced MapFS with clock simulation and symlink support
internal/testutil/harnessutil/harnessutil.go	Refactored tracer implementation for better baseline generation
internal/execute/*.go	Improved test system with better output handling and timing simulation
cmd/tsgo/main.go	Updated to use new CommandLine interface