F fix variables replacement lists

Summary

Variables were not replaced when the value of a property was given as a list, so the following case did not work:

records:
  Measurement:
    responsible:
    - $a
    - $b

This MR implements the replacement for lists and refactors the variable replacement.

Test Environment

There are unit tests provided.

Check List for the Author

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• All automated tests pass
• Reference related issues
• Up-to-date CHANGELOG.md (or not necessary)
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md (or not necessary)
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.