Deltashell currently has two interfaces that should be used to implement import functionality
IFileImporter : Can add items to a folder or can replace value of dataitem if that value matches the supported datatypes of the IFileImporter.
ITargetItemFileImporter : mutates it's TargetItem by importing stuff into it if TargetItem is set. If targetitemisRequired is false this importer can also function as a regular IFileImporter
These interface need review 