process: split bootstrappers by threads that can run them

This patch split part of the bootstrappers into three files:

- `lib/internal/process/main_thread_only.js`: contains bootstrappers
  that can only be run in the main thread, including
  - `setupStdio` for the main thread that sets up `process.stdin`,
    `process.stdout`, `process.error` that may interact with external
    resources, e.g. TTY/File/Pipe/TCP sockets
  - `setupProcessMethods` that setup methods changing process-global
    states, e.g. `process.chdir`, `process.umask`, `process.setuid`
  - `setupSignalHandlers`
  - `setupChildProcessIpcChannel` that setup `process.send` for
    child processes.
- `lib/internal/process/worker_thread_only.js`: contains bootstrappers
  that can only be run in the worker threads, including
  - `setupStdio` for the worker thread that are streams to be
    manipulated or piped to the parent thread
- `lib/internal/process/per_thread.js`: contains bootstrappers
    that can be run in all threads, including:
  - `setupAssert` for `process.assert`
  - `setupCpuUsage` for `process.cpuUsage`
  - `setupHrtime` for `process.hrtime` and `process.hrtime.bigint`
  - `setupMemoryUsage` for `process.memoryUsage`
  - `setupConfig` for `process.config`
  - `setupKillAndExit` for `process.kill` and `process.exit`
  - `setupRawDebug` for `process._rawDebug`
  - `setupUncaughtExceptionCapture` for
    `process.setUncaughtExceptionCaptureCallback` and
    `process.hasUncaughtExceptionCaptureCallback`

Hopefully in the future we can sort more bootstrappers in
`boostrap/node.js` into these three files and further group
them into functions that can be run before creating the
snapshot / after loading the snapshot.

This patch also moves most of the `isMainThread` conditionals
into the main bootstrapper instead of letting them scattered around
special-casing different implementations.

PR-URL: https://github.com/nodejs/node/pull/21378


Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>