SCRIPTS: Script modules are reused when they are imported (#461)

Also corrects some compile race conditions.

src/utils/helpers/getKeyList.ts

@@ -0,0 +1,18 @@
+/** Function for getting a list of keys to use for saving an object
+ * @param ctor the class constructor
+ *
+ * @param removedKeys Keys that exist on a default constructed member, but should not be saved.
+ *                    These keys will just revert to default values on load.
+ *
+ * @param addedKeys   Optional keys that do not exist on a default constructed member, but should be saved when present.
+ */
+export function getKeyList<T extends object>(
+  ctor: new () => T,
+  modifications?: { removedKeys?: readonly (keyof T)[]; addedKeys?: readonly (keyof T)[] },
+): readonly (keyof T)[] {
+  const newObj = new ctor();
+  const keySet = new Set(Object.getOwnPropertyNames(newObj)) as Set<keyof T>;
+  modifications?.removedKeys?.forEach((key) => keySet.delete(key));
+  modifications?.addedKeys?.forEach((key) => keySet.add(key));
+  return [...keySet];
+}