Notable changes:

bootstrap: implement run-time user-land snapshots via --build-snapshot
and --snapshot-blob

This patch introduces `--build-snapshot` and `--snapshot-blob` options
for creating and using user land snapshots.

To generate a snapshot using snapshot.js as an entry point and write
the snapshot blob to snapshot.blob:

```bash
echo "globalThis.foo = 'I am from the snapshot'" > snapshot.js
node --snapshot-blob snapshot.blob --build-snapshot snapshot.js
```

To restore application state from snapshot.blob, with index.js as the
entry point script for the deserialized application:

```bash
echo "console.log(globalThis.foo)" > index.js
node --snapshot-blob snapshot.blob index.js
```

Users can also use the `v8.startupSnapshot` API to specify an entry
point at snapshot building time, thus avoiding the need of an additional
entry script at deserialization time:

```bash
echo "require('v8').startupSnapshot.setDeserializeMainFunction(() => console.log('I am from the snapshot'))" > snapshot.js
node --snapshot-blob snapshot.blob --build-snapshot snapshot.js
node --snapshot-blob snapshot.blob
```

Contributed by Joyee Cheung in #38905

Other notable changes:

* crypto:
  * (SEMVER-MINOR) allow zero-length IKM in HKDF and in webcrypto PBKDF2
  (Filip Skokan) #44201
  * (SEMVER-MINOR) allow zero-length secret KeyObject (Filip Skokan) #44201
* doc:
  * add MoLow to collaborators (Moshe Atlow) #44214
  * add ErickWendel to collaborators (Erick Wendel) #44088
* http:
  * (SEMVER-MINOR) make idle http parser count configurable (theanarkh) #43974
* net:
  * (SEMVER-MINOR) add local family (theanarkh) #43975
* src:
  * (SEMVER-MINOR) add detailed embedder process initialization API (Anna
  Henningsen) #44121
  * (SEMVER-MINOR) print source map error source on demand (Chengzhong
  Wu) #43875
* tls:
  * (SEMVER-MINOR) pass a valid socket on `tlsClientError` (Daeyeon
  Jeong) #44021
* worker:
  * deprecate `--trace-atomics-wait` (Keyhan Vakil) #44093