Extending the code

[msblim]

How can we improve this code to make it easily extendable? For example, in the following iterations of the code, we are asked to improve the features, say improve the user interface.

[lopezpaolot]

Moved most of the implementation to separate classes so that we can easily extend the code in the future. Fixed on branch "issue4_fix" merged to main in commit https://github.com/lopezpaolot/itrsExam/commit/a7c5f104b580908f5e8c6fbf37cbe6cda5fb0f04.