Implementation for "Copy Qualified Name" (#1001257)

This is a first implementation for "Copy Qualified Name". The GUI interacts with ScalaCopyQualifiedNameAction, with extends and eventually delegates to the corresponding Java class. The actual works happens in NamePrinter.

I'm still planning to do some tweaks/changes/feature additions, but I wanted to share this with you early.
I don't think we need the super class, you can directly extend `Action`. The only important lost (as far as I can see) is the message dialog in case nothing is selected. But I wouldn't display a message dialog in such cases anyway, just clean the clipboard or leave it untouched. When nothing is selected then there is no outcome.