Implement typed generic wrapper for IBackgroundServiceHealthService

[Anders-Toegersen]

Background:

The current implementation of IBackgroundServiceHealthService uses a string (serviceName) to register and manage the health check state of a background service. As the background services are registered as singletons, we can use the type to make a unique service name.

Proposed Changes:

1. Implement IBackgroundServiceHealthService<TBackgroundService> that utilizes the type TBackgroundService to create a unique name to call into IBackgroundServiceHealthService.

Impact:

• Increased ease of use as we reduce the boilerplate of finding the serviceName for each call.
• Reduced chance of errors as the call can be made more consistent.
• Added complexity for service registration of IBackgroundServiceHealthService<TBackgroundService>

[Anders-Toegersen]

The new IBackgroundServiceHealthService<TBackgroundService> could look like this:

public interface IBackgroundServiceHealthService<TBackgroundService>
{
    void SetMaxStalenessInSeconds(ushort seconds);

    void SetRunningState(bool isRunning);

    bool IsServiceRunning();
}

and be consumed like this:

public class MyBackgroundService : BackgroundServiceBase<MyBackgroundService>
{
    private readonly IBackgroundServiceHealthService<MyBackgroundService> healthService;

    public MyBackgroundService(IBackgroundServiceHealthService<MyBackgroundService> healthService)
    {
        this.healthService = healthService;
    }

    public override async Task DoWorkAsync(CancellationToken stoppingToken)
    {
        ....
        healthService.SetRunningState(true);
        ....
    }
}