Make Module configuration easy

[cijothomas]

Provide an ability to configure any TelemetryModule in an easy way as opposed to the following documented way.

Configuring Telemetry Module Services
Inorder to configure any properties of TelemetyModules, obtain the module from DI Container first. Then modify the required properties, and re-initialize the module with currently active Telemetry Configuration.

For eg:, to modify DependencyTrackingTelemetryModule to disable setting Correlationheaders, the following code is required in the Configure method of you Startup class.

DependencyTrackingTelemetryModule dep;
var modules = app.ApplicationServices.GetServices();
foreach(var module in modules)
{
if (module is DependencyTrackingTelemetryModule)
{
dep = module as DependencyTrackingTelemetryModule;
dep.SetComponentCorrelationHttpHeaders = false;
dep.Initialize(TelemetryConfiguration.Active);
}
}

[cijothomas]

Addressed via https://github.com/Microsoft/ApplicationInsights-aspnetcore/pull/632/files

To configure a telemetry module, use the extension method ConfigureTelemetryModule<T>(Action <T> configModule) on IServiceCollection. This should be done in the ConfigureServices() method of Application's Startup.cs class.

For example, the following shows how to configure DependencyTrackingTelemetryModule

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddApplicationInsightsTelemetry();
            services.ConfigureTelemetryModule<DependencyTrackingTelemetryModule>((module) => {                    
dep.SetComponentCorrelationHttpHeaders = false;
                });
        }