Challenge51: Misconfiguration of docker secret in code

[Shubham-Patel07]

What kind of changes does this PR include?

• [ ] Fixes or refactors
• [x] A new challenge
• [ ] Additional documentation
• [ ] Something else

Description

New challenge created for misconfiguration of docker secret in code.

Relations

Relates #811

Checklist:

• [x] All the contributions made are solely the work of me and my co-authors
• [ ] I tested the changes in this PR (if applicable)
• [ ] I added unit tests to ensure my change works (when change in Java or on front-end code)
• [ ] I added UI tests to ensure my UI changes work (when change in the overall UI, not needed if just adding a challenge)
• [ ] The PR passes pre-commit hooks and automated tests