smoke tests - automatically test against stable build

[bpasero]

This PR attempts to include the smoke tests that are usually only running when you provide --stable-build in our CI to fully automate smoke tests and not having to run them in endgame.

By using our existing vscode-test module it is relatively easy to download latest stable bits.

However, when I run the following command for the first time in a fresh checkout:

yarn smoketest --build /Users/bpasero/Desktop/Visual\ Studio\ Code\ -\ Insiders.app

I am greeted with this error:

  1) VSCode Smoke Tests (Electron)
       Stable vs Insiders Smoke Tests: This test MUST run before releasing
         Datamigration
           verifies opened editors are restored:
     Error: connect ENOENT /var/folders/fv/p__j7gw9097crr40g7sf2pxw0000gn/T/tmp-8451c917E3g5M20a
      at PipeConnectWrap.afterConnect [as oncomplete] (node:net:1133:16)

  2) VSCode Smoke Tests (Electron)
       Stable vs Insiders Smoke Tests: This test MUST run before releasing
         Datamigration
           verifies that 'hot exit' works for dirty files:
     Error: connect ENOENT /var/folders/fv/p__j7gw9097crr40g7sf2pxw0000gn/T/tmp-8451dPWOrpoUbcmm
      at PipeConnectWrap.afterConnect [as oncomplete] (node:net:1133:16)

When I run again, it works fine. vscode-test is storing the downloaded bits into a .vscode-test folder in test/smoke and will not download it again if it is found there.

I tried all things like adding a timeout to ensure the build is there but couldn't figure it out. Need your help @joaomoreno if you maybe got further ideas what this could be.

[bpasero]

Interesting, in the CI that ENOENT error does not appear though the second test fails: https://dev.azure.com/monacotools/Monaco/_build/results?buildId=126043&view=logs&j=4d2898ab-dfbe-557e-92e7-aaac158fdd2f&t=dccbe8b6-2cf2-56ce-ca99-720e7791a9c0&l=28