Creatures are now cached in memory for computation

Also removed dependency group calculation because the optimisation isn't
as useful to reduce DB calls if the creature is in memory anyway

app/imports/api/engine/computation/writeComputation/writeAlteredProperties.js

@@ -20,7 +20,6 @@ export default function writeAlteredProperties(computation){
       'deactivatedBySelf',
       'deactivatedByAncestor',
       'deactivatedByToggle',
-      'depGroupId',
       'damage',
       ...schema.objectKeys(),
     ];