Support specifying PowerShell Module Version

[russellds]

It would be extremely helpful if you could specify the version of the PowerShell module(s) to be installed. There are times where I need a specific version, typically with the Azure PowerShell module, because of issues with the latest version.

A simple way to do it would be to seperate the module and version with a colon, see below. If the version is not specified, then install the latest as it currently works.

"ghcr.io/devcontainers/features/powershell:1": {
      "version": "latest",
      "modules": "powershell-yaml,Az:11.4.0"
    }