fix: Standardize getModuleVersionChanges return type

[guilhermelimak]

Avoid returning false (which as far as I can see was not being used in any case) and always return an object.

Closes #172

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[simoneb]

Whenever we fix a bug, always add a unit test on that specific bug to prevent a regression and confirm that the change actually fixes it. Write a failing test which exposes the issue, then fix the issue and see the test succeeding.

[simoneb]

LGTM, good job