TypeScript: use `createFileSystemWatcher` for file events

[bpasero]

Refs: #193848

• need to check for TS 5.4 at least
• optimisations
  • pass down need for update/create/delete events all the way down into watcher for correlated requests?
  • deduplicate watchers that correlate to reduce file handles need?
• is TS deduplicating watch requests on same paths?
• explore how fs.watch behaves when npm i or git co
• we should batch events in the extension and only emit in chunks to prevent 1 IPC call per event?
• enable the setting as experiment, default for insiders but disabled by default (!)
• see if TypeScript file watcher holds onto folders and causes EPERM TypeScript#54087 is better then
• explore file access with setting enabled using ProcMon on Windows

cc @sheetalkamat

[bpasero]

File Access After:

File Access Before:

[bpasero]

This is done and behind an experiment that we will enable gradually in stable.

[BurningEnlightenment]

The current implementation seems to be incompatible with how yarn hooks the SDK to allow access to PnP packages.