Check if all services are registered

[linkdotnet]

Follow up to #177

Check if all jobs and their dependencies are registered probably (inside UseNCronJob).

Additional info:

• We want to offer this in the ASP.NET style:

builder.Host.UseDefaultServiceProvider((_, options) =>
{
    options.ValidateScopes = true;
    options.ValidateOnBuild = true;
});

So, basically, UseNCronJob gets an optional parameter with an options object that has a ValidateOnBuild flag as well. And if IsDevelopment is true we might even wanna enable that to be aligned with ASP.NET.

• We might want to include Minimal Jobs as well. But that means we have to dissect the lambda.