Provide HTTP client message handler to propagate dependency ID (option #1)

[stijnmoreels]

Is your feature request related to a problem? Please describe.
When sending out a HTTP message, we need to track it as a HTTP dependency in Application Insights. To link the correlation between services, we need to propagate the dependency ID to the HTTP telemetry model and enrich the HTTP headers with the correlation information.

Describe the solution you'd like
Option 1 is to create an HTTP message handler that we can register in the Dependency Injection container, so the IHttpClient that is used throughout the application is enriched with this custom message handler.
These message handlers are scoped dependencies, so we can inject our ICorrelationInfoAccessor easily to have access to the current correlation information.

Describe alternatives you've considered
Option 2: where we provide and extension on the HttpClient #258.

Additional context
https://thomaslevesque.com/2016/12/08/fun-with-the-httpclient-pipeline/
https://github.com/arcus-azure/arcus-service-to-service-correlation-poc
https://docs.microsoft.com/en-us/aspnet/core/fundamentals/http-requests?view=aspnetcore-5.0

[stijnmoreels]

This issue is now dependent on the outcome of this discussion probably: arcus-azure/arcus-service-to-service-correlation-poc#6

[stijnmoreels]

So, I'm guessting this will be low-prio too together with #258 bc we will first focus on receival?