Use `access` on *nix and `GetFileAttributesW` on Windows.
[Benchmark](https://paste.divy.work/p/-gq8Ark.js):
```
$ deno run -A bench.mjs # main (568dd)
existsSync: 8980.636629ms
$ target/release/deno run -A bench.mjs # this PR
existsSync: 6448.7604519999995ms
$ bun bench.mjs
existsSync: 6562.88671ms
$ node bench.mjs
existsSync: 7740.064653ms
```
Ref https://github.com/denoland/deno/pull/24434#discussion_r1679777912
Part of #18218
- Adds `fs.lutimes` and `fs.lutimesSync` to our node polyfills. To do
this I added methods to the `FileSystem` trait + ops to expose the
functionality to JS.
- Exports `fs._toUnixTimestamp`. Node exposes an internal util
`toUnixTimestamp` from the fs module to be used by unit tests (so we
need it for the unit test to pass unmodified). It's weird because it's
only supposed to be used internally but it's still publicly accessible
- Matches up error handling and timestamp handling for fs.futimes and
fs.utimes with node
- Enables the node_compat utimes test - this exercises futimes, lutimes,
and utimes.
