Denormalized some calculations into recomputation step

app/imports/api/properties/SavingThrows.js

@@ -1,4 +1,5 @@
 import SimpleSchema from 'simpl-schema';
+import ErrorSchema from '/imports/api/properties/subSchemas/ErrorSchema.js';
 
 // These are the rolls made when saves are called for
 // For the saving throw bonus or proficiency, see ./Skills.js
@@ -18,4 +19,22 @@ let SavingThrowSchema = new SimpleSchema ({
   },
 });
 
-export { SavingThrowSchema };
+const ComputedOnlySavingThrowSchema = new SimpleSchema({
+  dcResult: {
+    type: Number,
+    optional: true,
+  },
+  dcErrors: {
+    type: Array,
+    optional: true,
+  },
+  'dcErrors.$':{
+    type: ErrorSchema,
+  },
+});
+
+const ComputedSavingThrowSchema = new SimpleSchema()
+  .extend(SavingThrowSchema)
+  .extend(ComputedOnlySavingThrowSchema);
+
+export { SavingThrowSchema, ComputedOnlySavingThrowSchema, ComputedSavingThrowSchema };