Use DirectoryPath type for passing path to aliases

[pascalberger]

The DockerBuild alias currently expects the path as a string. It would be more "Cake-like" if path parameter would be of type DirectoryPath.

Maybe there are also other places where DirectoryPath or FilePath can be used.

[MihaMarkic]

@pascalberger You are certainly correct. The thing was, that most of the settings were autogenerated from sources, where it isn't evident what string represents. Since then I dropped autogeneration (too fuzzy) and settings are manually added/changed. So, yes, we can slowly replace them where it fits - it isn't a breaking change, right?

[pascalberger]

It shouldn't be breaking as you still can pass a string afterwards

[MihaMarkic]

Good. I will keep in mind this, and if somebody provides PRs, I'll gladly merge them.