Argo workflow with an upload step nfs

[katilp]

After #33:

Add a new argo workflow in the nfs cluster folder with and additional step to upload the file to the nfs disk

It can use image: rootproject/root:latest

and the command to copy files from their storage is

xrdcp <file path as in the file list from cernopendata-client> .

Modify the input file list for the processing step so that it lists:

file:filename1.root
file:filename2.root
[...]

instead of

root://eospublic.cern.ch//eos/opendata/cms/[...]/filename1.root
root://eospublic.cern.ch//eos/opendata/cms/[...]/filename2.root

where filename1 etc are placeholders for the actual file names.

Test that it works.