`tools` directory size: only download/bundle right OS?

[cben]

I was low on disk space and saw that this extension was the biggest under ~/.vscode/extensions/, with out/tools directory containing binaries for 3 OSes:

  131.1 MiB [##############] /darwin                                                                    
  119.8 MiB [############  ] /linux
  118.2 MiB [############  ] /win32

If it's possible to only install the one for user's OS, it would save space & traffic on upgrades.

[dgolovin]

It is going to be fixed as part of #2235.