perf(ext/node): convert node:path to lazy-loaded JS (#33917)
Converts `node:path` and its internals from eagerly-loaded ESM to
lazy-loaded JS:
- `path/_posix.ts`, `path/_win32.ts`, `path/mod.ts` → IIFE in
`lazy_loaded_js`
- `path.ts`, `path/posix.ts`, `path/win32.ts` → thin ESM wrappers in
`lazy_loaded_esm`
- `node:process` dependency handled via `core.createLazyLoader`
`node:path` is a widely-imported dependency — making it lazy unblocks
converting many downstream modules (e.g. `internal/fs/utils.mjs`, fs
helpers, etc.) that currently depend on it.
