CORE-6039 filesystem services use util.config in namespace

The util.config namespace is aliased as cfg in the donkey.services.fileystem namespaces.
CORE-6039 manifest uses aliased tree-urls namespace
CORE-6039 alphabetized some donkey.services.filesystem uses

This helps with figuring out dependencies.
CORE-6039 removing dead code making internal fns private
CORE-6039 removing dead code making internal fns private
CORE-6039 filesystem route uses aliased service.filesystem namespaces
CORE-6039 added missing slingshot dependency to donkey project
CORE-6039 remove bogus deps on filesystem namespace
CORE-6039 removed unused method get-avus