think about getting rid of 'path' subfolder in file repository

[ltalirz]

If one does node repo ls on, for example, a SinglefileData node that is expected to contain a file, one currently gets

$ verdi node repo ls -p 5
path

To somebody who doesn't already know about the path subfolder it is unclear what is going on - is it an error? Where are my files?

Furthermore, the path subfolder is yet another complication in the file hierarchy.
We should investigate whether we can get rid of it or at least make the verdi node repo commands more user-friendly.