Add test coverage improvements, Maven dev profile, and ConsoleInterceptor

[J-manLans]

• [x] I have read CONTRIBUTING.md.
• [x] This pull request is all my own work -- I have not plagiarized it.
• [x] All filenames are in PascalCase.
• [x] All functions and variable names follow Java naming conventions.
• [x] All new algorithms have a URL in their comments that points to Wikipedia or other similar explanations.
• [x] All new code is formatted with clang-format -i --style=file path/to/your/file.java

This PR is part of a test course project and includes the following improvements:

• Expanded test coverage for the most under-tested packages, improving overall code reliability.
• Optional Maven dev profile added to allow developers to easily switch between classes and generate reports for PIT mutation testing.
• ConsoleInterceptor implementation to simplify testing of classes that heavily rely on console input/output. (not thread-safe)
• Minor refactors to improve testability without changing core logic

Notes:

• Focus on ConsoleInterceptor usage and test coverage improvements.
• For a thread-safe version of the interceptor, it might be beneficial to consider enforcing scanners and console output via constructor injection to allow mocking of streams.