Add Code Coverage and Clang-tidy

[AdityaPandeyCN]

This PR adds Code coverage and clang-tidy workflow to the project.
The changes made are:-

1. Added Code Coverage Infrastructure

• Created .codecov.yml configuration with 85% coverage target for new code
• Added GitHub Actions coverage job that runs tests and generates coverage reports
• Added ENABLE_COVERAGE CMake option

2. Added Static Code Analysis

• Created .github/workflows/clang-tidy-review-post.yml for automated code review
• Configured clang-tidy to post review comments on PRs (max 10 comments)
• Set up CI to fail on clang-tidy warnings

3. Fixed Build Dependencies

• Created generate_sam.cxx to separate SAM file generation from benchmark code
• Refactored sam_generator library to be available for tests without benchmark dependency
• Updated CMake to include benchmark directory when tests OR benchmarks are enabled
• Resolved circular dependency that prevented tests from building independently

4. CMake Improvements

• Added coverage build configuration with gcovr and lcov
• Created make coverage target for local coverage generation
• Fixed conditional compilation of test utilities

[codecov-commenter]

Welcome to Codecov 🎉

Once you merge this PR into your default branch, you're all set! Codecov will compare coverage reports and display results in all future pull requests.

Thanks for integrating Codecov - We've got you covered ☂️

[AdityaPandeyCN]

The chromosome test is flaky passes locally but sometimes fails here

[vgvassilev]

The chromosome test is flaky passes locally but sometimes fails here

That’s an indicator of a problem. Can you run with valgrind?

[AdityaPandeyCN]

It was a race condition I have fixed it using global mutex.

[vgvassilev]

Lgtm!