Backport of autopilot: add `operator autopilot health` command into release/1.7.x

[hc-github-team-nomad-core]

Backport

This PR is auto-generated from #20156 to be assessed for backporting due to the inclusion of the label backport/1.7.x.

The below text is copied from the body of the original PR.

---

Add a command line operation that reports Enterprise autopilot data from the /operator/autopilot/health API. I've pulled this feature out of @lindleywhite's PR in the Enterprise repo.

Ref: https://github.com/hashicorp/nomad-enterprise/pull/1394

---

Overview of commits

• c4253470a0401ef1b8538c7618aaea84e2c8ad7d