Adding rucio functionality for km3net

These are things that would be nice for km3net to have:

• Getting intersections of dids in datasets / containers:

  The snippet below gets duplicates from two containers, but it is hacky and can be

  • generalized to work with any number of datasets
  • be a python fuction
  • be merged back to rucio

  files=""
  for f in "CORSIKA_testing:Prod-TeV_low" "CORSIKA_testing:Primary-p"; do 
    tmp=`rucio list-files --csv $f | uniq`
    files+=$'\n'"$tmp" 
  done 
  echo "$files" | sort | uniq -d