Adds a Windows service example

[kennykerr]

This sample illustrates how to write a Windows service directly using the Service Control Manager (SCM) and with the help of the windows-sys crate. Once built, you can install the service (from an admin prompt) as follows:

> sc create rust binPath= D:\git\windows-rs\target\debug\sample_service_sys.exe

You can then use the various SCM commands to control the services:

> sc start rust
> sc pause rust
> sc continue rust
> sc stop rust

I do plan to provide a more idiomatic windows-services crate but this should help get you started if you need to write a Windows service for the time being.

[Copilot]

Pull Request Overview

This pull request adds a new Windows service example written in Rust using the windows-sys crate. Key changes include:

• A new sample implementation for a Windows service, including service control management and thread management.
• Addition of a Cargo package configuration for the sample.
• Updates to GitHub workflows to include tests for the new sample.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
crates/samples/windows-sys/service/src/main.rs	Implements the Windows service sample with SCM integration and logging
crates/samples/windows-sys/service/Cargo.toml	Adds package metadata and dependencies for the sample service
.github/workflows/test.yml	Updates workflow to run tests for the newly added service sample