Correct surface currents tally on Python side, throw error if not in CE mode
Correct surface currents tally on Python side, throw error if not in CE mode

walshjon/openmc,amandalund/openmc,amandalund/openmc,walshjon/openmc,paulromano/openmc,wbinventor/openmc,wbinventor/openmc,shikhar413/openmc,liangjg/openmc,shikhar413/openmc,smharper/openmc,paulromano/openmc,amandalund/openmc,liangjg/openmc,mit-crpg/openmc,shikhar413/openmc,liangjg/openmc,wbinventor/openmc,walshjon/openmc,shikhar413/openmc,liangjg/openmc,smharper/openmc,amandalund/openmc,mit-crpg/openmc,mit-crpg/openmc,paulromano/openmc,mit-crpg/openmc,walshjon/openmc,paulromano/openmc,smharper/openmc,smharper/openmc,wbinventor/openmc