[Server][FaceRest] Fix wrong name.

targetHostGroupId ->
targetHostgroupId
          ^
[Server][DBClientHatohol] Change argument of getHostGroupIdColumnName()
function.

items, triggers and events table doesn't have Hostgroup ID column.
[Server][DBClientHatohol] Change a function name.

getHostGroupIdColumnName ->
getHostgroupIdColumnName
       ^