Remove built-in dependencies

[streamich]

Review and try to remove built-in Node.js module dependencies, so they are not bundled when building for web.

• path
• process
• stream — is there a way to make the stream module optional?
  • Or maybe explicitly install readable-stream as required dependency.
• buffer — create a thin wrapper around Uint8Array, when Buffer global is missing.
• util
  • util.inherits()
• Error messages
  • internal/errors.ts — Node-like errors vendored module
  • assert
    • assert.strictEqual()
    • assert()
  • url
    • url.URL
  • util
    • util.format()
    • util.inspect()

[abhishiv]

Hey @streamich shouldn't this list include stream as well since memfs uses Readable, Writable?

[streamich]

We will always need some stream implementation, due to fs.createReadStream() and fs.createWriteStream().

Maybe we could explicitly install readable-stream dependency, instead of relying on Node's built-in stream.