Add sshd into workspace default devfile

MR: Pending

Description

Follow up on the Slack discussion, we would like to add sshd into workspace default image.

Also need to decide if we would like to update in install-essential script or just in our own dockerfile.

Acceptance criteria

• Decide where to install openssh-server for workspace default image (likely not install-essential)
• Install and publish default image
• Update GitLab to use latest workspace default image

Implementation plan

TODO: Fill out or delete (optional)

[Provide a high-level plan for implementation of this issue, including relevant technical and/or design details.]