fix: update docstring for explicit function behavior description

[mcllerena]

This PR adds a more detail description of what the add_report() function does when modyfing an existing report for adding a new property to it. It also resolves any formatter existing issues for CI passing and adds a relevant tests to prove the existing function behavior.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.15%. Comparing base (fd605d0) to head (936ac13).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #176      +/-   ##
==========================================
- Coverage   96.22%   96.15%   -0.07%     
==========================================
  Files          20       20              
  Lines        3151     3097      -54     
==========================================
- Hits         3032     2978      -54     
  Misses        119      119              

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