Revise checks for opr users

[ZLLentz]

Expected Behavior

Checks for operator users should only find operator users.

Current Behavior

Most checks are implemented via checking if the username contains "opr", which will give false positives for some (rare) users.

Possible Solution

Check specifically for the hutch operator accounts in /cds/home/opr instead:

$ ls /cds/home/opr
cxiopr  detopr  feeopr  hplopr  lasopr  mccopr  mecopr  mfxopr  rixopr  tmoopr  tstopr  txiopr  uedopr  xcsopr  xppopr

Context

#204 (comment)