fix issue #298

[dodu94]

Description

This commit fixes #298 that was due to the LibManager operating directly on the library dataframe of the configuration instead of on a copy of it. Tests have been added to cover for this bug in the future

Fixes #298

Type of change

Please select what type of change this is.

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New benchmark
  • [ ] Non-breaking change which entirely uses exisiting classes, structure etc
  • [ ] Breaking change which has implemented new/modified classes etc
• [ ] New feature
  • [ ] Non-breaking change which adds functionality
  • [ ] Breaking change fix or feature that would cause existing functionality to not work as expected

Testing

Error has been reproduced with CI testing and then solved

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [ ] General testing
  • [x] New and existing unit tests pass locally with my changes
  • [x] Coverage is >80%