FLUID-4976: Renamed the base enactor grade from "enactors" to "enactor".
FLUID-4976: Rename the filename or events that has "enactors" to "enactor".
Merge remote-tracking branch 'cindyli/FLUID-4976'

* cindyli/FLUID-4976:
  FLUID-4976: Rename the filename or events that has "enactors" to "enactor".
  FLUID-4976: Renamed the base enactor grade from "enactors" to "enactor".
Merge branch 'master' into FLUID-4927
FLUID-4927: Comply to the renaming of enactors to enactor.