Project refresh on Windows is too slow

[Tyriar]

Describe the bug

Setup:

  "gitProjectManager.baseProjectsFolders": [
    "$HOME/dev",
    "D:\\dev"
  ],
  "gitProjectManager.maxDepthRecursion": 2,

When I reload the window, I hit my keybinding and wait for extension activation. Once that's done the quick pick appears immediately but the search to refresh the project list typically takes 5+ seconds even though I have the following structure:

Tyriar
  (19 git folders, 1 zip file)
Microsoft
  (6 git folders, 1 build output folder)
xtermjs
  (1 folder)

It seemed to dramatically speed up (~5s -> ~2s) when I deleted the build output folder (packaged VS Code) and the zip file, but it's still unreasonably slow imo. Looking at the code I get the impression the issues are caused almost completely by sync calls from this extension to the file system, since walker is all async.

Something else that might be slowing things down is that readdir may be called on folders at depth n but the results are discarded?