Ensure Quiz Linter refreshing on Quiz changes that do not change the slide structure

Due to a bug probably introduced with #19 (closed) the Quiz Linter did not update correctly when the Quiz was updated without changing the structure of the slides (e.g., the slide order, amount of slides and question blocks remained the same).

This meant that when for example adding answers, the Quiz Linter would not update, as this does not change the structure of the Quiz, only the contents. This has been fixed by adding a simple check to ensure that if the Quiz is changed the Linter is updated.

This fixes #46 (closed)