[FEATURE][API] Make the FileHandlingUtility usable for ext:coreapi

Currently there are no informations if the upload folders were
created by ensureConfiguredDirectoriesExist(). Some feedback to
the user on CLI it would be nice.

This added some status messages and returns them inside an array.

Furthermore the patch make method
getAbsolutePathsToConfiguredDirectories() public to make it usable
in CommandControllers.

Resolves:
Releases: 6.2, 6.3
Change-Id: If516f9020a7625fc23b9715248c7b0b3668d24ce