feat(engine262): add verify-ask262 script and relocate verify‑ask262‑debug

- Moved `verify-ask262-debug.mts` from `scripts` to `lib-src/node`.
- Updated import to use `#self` alias.
- Added npm script `verify-ask262` to run the verification script.
- Adjusted `scripts/tsconfig.json` to include the new file location.

engine262/scripts/tsconfig.json

@@ -1,6 +1,6 @@
 {
   "extends": "../tsconfig.base.json",
-  "include": ["."],
+  "include": [".", "../lib-src/node/verify-ask262-debug.mts"],
   "compilerOptions": {
     "noEmit": true,
     "erasableSyntaxOnly": true,