Allow Socket Task API to talk to a proxy instead Nomad directly

### Proposal

Nomad Task API Socket looks great, but in some scenarios the Nomad Server might be behind some proxies that your request should be looped through.

### Use-cases

In my case, I am building an [Admission Controller Proxy](https://github.com/mxab/nacp) that validates/modifies Nomad jobs on the fly. Currently the Unix socket prevents the proxy from being enforced.

My request relates to my [community hour question
](
https://www.youtube.com/live/UO0yToiVPKE?feature=share&t=2835)

Start with the Nomad Task API Socket entry point; the issue names no files or tests. Review how requests currently reach Nomad directly and determine the proxy configuration and routing behavior needed for the admission-controller use case. Done means the socket API can communicate through a proxy instead of requiring direct access to Nomad.

Written by the indexing model from the issue text.