Make it possible to restrict scopes and types to some paths

[ejpcmac]

Rationale

Even with a description, humans being humans, we may end up using an incorrect scope or type for a commit updating some part of the repository where the scope or type would not apply. git-z is about making such kinds of errors very unlikely, so let’s find some way to avoid that from the beginning.

Concept

Let’s make it possible to define a list of acceptable paths for each type or scope, and use them both in the wizard and validator.