ExtendedPropertyDefinition imports removed `util.isNullOrUndefined` — breaks on Node 24+

[perbergland]

Problem

src/js/PropertyDefinitions/ExtendedPropertyDefinition.ts imports isNullOrUndefined from Node's built-in util module:

import { isNullOrUndefined } from "util";

util.isNullOrUndefined was runtime-deprecated years ago (DEP0054) and has now been removed from Node.js. On Node 24 (and confirmed on Node 25) the import resolves to undefined:

$ node -v
v25.8.1
$ node -e "console.log(typeof require('util').isNullOrUndefined)"
undefined

Any code path that reaches ExtendedPropertyDefinition then throws TypeError: isNullOrUndefined is not a function.

Note

The library already ships its own isNullOrUndefined in src/js/ExtensionMethods.ts (with identical semantics: obj === undefined || obj === null), and every other call site in the codebase already imports it from there. This one file is the only place still pulling the removed Node built-in.

Fix

Import isNullOrUndefined from ../ExtensionMethods instead of "util". No new dependency, no behavior change. PR follows.