Retry Mechanism for Package Testing

[j1shnu]

Checklist

• make test-all (UNIX) passes. CI will also test this
• unit and/or integration tests are included (if applicable)
• documentation is changed or added (if applicable)

Description of change

Added retry mechanism for package testing. Details are mentioned in issue #1034. The goss file syntax will be the following:

package:
  httpd:
    retry: true             # Enables retry mechanism
    retry_delay: 180        # Delay (in seconds) before retrying the check
    installed: true
    name: httpd
    versions:
      - 2.2.15
    skip: false

---

📚 Documentation preview 📚: https://goss--1037.org.readthedocs.build/en/1037/