Copy files to different location (duplicate files)

[andamian]

See opencadc/vostools#206

[pdowler]

Is this within one VOSpace or from one to another (eg arc -> vault or vice versa)?

We can and should implement this, but I have proposed some changes to transfers for VOSpace-next (2.2) and we should probably refine that proposal and implement that draft as a prototype.

[andamian]

Within the same VOSpace.