Unpublish specific version command

[tooltitude-support]

Th API which is used by vsce, has delete extension command: https://learn.microsoft.com/en-us/javascript/api/azure-devops-extension-api/galleryrestclient#azure-devops-extension-api-galleryrestclient-deleteextension

Would nice to use it to provide delete extension command on vsce.

P.S. I tried changing vsce to support this. Unfortunately, it failed with the following error message:

  statusCode: 400,
  result: { count: 1, value: { Message: 'The request is invalid.' } },

[benibenj]

Closing as this is an upstream issue which is unlikely to be resolved any time soon