Improve process implementation

[mvz]

Summary

Improve Process robustness

Details

TBA. At least the specs for Command#stop and Command#terminate are a bit clearer

Motivation and Context

Random failures in CI

How Has This Been Tested?

CI.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Documentation update
• [ ] Internal change (refactoring, test improvements, developer experience or update of dependencies)

Checklist:

• [ ] I've added tests for my code
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.