feat(controller): Add support for Docker workflow executor for Windows nodes

[lippertmarkus]

Argoexec already works with Windows Containers but didn't support docker workflow executor yet as Windows Containers require a different way of mounting the Docker socket (see kubernetes/kubernetes#69484):

• Path: \\.\pipe\docker_engine
• Type: null
• ReadOnly: false

I adapted the workflow controller to allow for different volume setups for Windows or Linux Steps of a workflow. When the following nodeSelector entry is present for a step in a workflow, then the volume setup for Windows is used, else the setup for Linux is used:

nodeSelector:
  kubernetes.io/os: windows

I also adapted the documentation as you not longer need to use the kubelet workflow executor.

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this is a chore.
• The title of the PR is (a) conventional, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234".
• I've signed the CLA.
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
  • not needed
• My builds are green. Try syncing with master if they are not.
• My organization is added to USERS.md.

[alexec]

Sorry for the late review. I've got just one comment and you'll need to fix conflicts so we can merge. Great work!

[lippertmarkus]

Thanks for reviewing, I fixed all conflicts and the naming of the function now.