refactor factory to return result(list(string), list((string,list(string))))

Currently a factory returns `result(unit, string)`.
For better console output `result(list(string), list(string))` is desired.
`Ok` will hold a list of the fabrics' name which was processed sucessfuly by the factory.
`Error` will hold a list of tuples holding fabrics name and a list of errors per fabric.