fix(logging): log better details of permission config errors

Author: sleidig

src/app/core/permissions/ability/entity-ability.ts

@@ -66,7 +66,7 @@ export class EntityAbility extends Ability<[EntityAction, string | any]> {
     } else if (entity.ENTITY_TYPE) {
       return entity.ENTITY_TYPE;
     } else {
-      throw new Error(`${entity} is not a valid subject`);
+      throw new Error(`${JSON.stringify(entity)} is not a valid subject`);
     }
   }
 }