(PUP-3462) Hiera scope: add the key 'calling_class_path' 

calling_class_path is calling_class with :: replaced by a /

This enables to have the class hiera yaml files in directories and enables to have class based hiera data on windows which does not allow ":" in path names.
According https://docs.puppetlabs.com/puppet/latest/reference/lang_reserved.html#classes-and-types accepatable names for classes are [a-z][a-z0-9_]* and namespaces seprated by "::". 

so this would give us "-" as "::" replacement too. 

But i think it would be confusing to use "-" (or any other acceptable character) in hiera and directories for puppet manifests.