Copy objects
S3 has the functionality to copy objects. This could be easily achieved by just a get and a put request right after one another.
Special attention has to be given to the phobos_file class, since this is not really setup for several phobos request after each other (had bugs in the past).
The API for copying objects can be found here: https://docs.aws.amazon.com/AmazonS3/latest/API/API_CopyObject.html