Add windows support for interactive web terminals.
## Description
In %11.3 support for [interactive web terminals](https://docs.gitlab.com/ee/ci/interactive_web_terminal/) was added. However [windows is not supported](https://docs.gitlab.com/runner/executors/README.html#compatibility-chart). In https://gitlab.com/gitlab-org/gitlab-ce/issues/25990#note_106621022 we are already getting some requests for this.
## Proposal
No technical proposal yet, but this should work the same as bash and any other executor.
## Links to related issues and merge requests / references
https://gitlab.com/gitlab-org/gitlab-ce/issues/25990#note_106621022
gitlab-org/gitlab-runner!934
issue