Update PR 901 to add --websocket flag

[KernelDeimos]

This PR updates #901 so that it adds the flag --websocket to the implementation that was already merged

Contributor checklist

• Provide tests for the changes (unless documentation-only)
• Documented any new features, CLI switches, etc. (if applicable)
  • Server --help output
  • README.md
  • doc/http-server.1 (use the same format as other entries)
• The pull request is being made against the master branch

Maintainer checklist

• Assign a version triage tag
• Approve tests if applicable

[KernelDeimos]

Going to merge. One test failed but this occurred because of an EADDRINUSE exception which is known to happen due to race conditions in the unit tests when they try to spin up testing servers.

This was thought to be fixed by ensuring ephemeral ports are always used. It's likely there are still some places where this was missed.