search for id with given name, return "<name>:<id>"
  // return
  //     getent group <name> | cut -d: -f1,3
  // OR
  //     id -u <name> | awk '{print "<name>:"$1 }'
search for id with given name, return "<name>:<id>"
  // return
  //     getent group <name> | cut -d: -f1,3
  // OR
  //     id -u <name> | awk '{print "<name>:"$1 }' | ShellBasedIdMapping.java