Introduce new type for policy on how to handle overwrite questions

[AntonHermann]

Currently, the handling of whether to ask questions and if not how to answer them currently uses

skip_questions_positively: Option<bool>

From this alone, it isn't obvious what the possible values mean. Is None a no? Does Some(false) mean not to skip questions positively? This still is not the same as skipping them negatively.

I think introducing a new enum here makes this more clear:

enum QuestionPolicy {Ask, AlwaysYes, AlwaysNo}

makes it obious what is supposed to happen and in my opinion the code more readable.

[marcospb19]

Awesome, I 100% agree, thanks!