feat(utils): configure open telemetry tracing for masstransit in aspn…

…et package (#1344)

<!--- Provide a general summary of your changes in the Title above -->

## Description

<!--- Describe your changes in detail -->

## Related Issue(s)

- #1262 

## Verification

- [ ] **Your** code builds clean without any errors or warnings
- [ ] Manual testing done (required)
- [ ] Relevant automated test added (if you find this hard, leave it and
we'll help out)

## Documentation

- [ ] Documentation is updated (either in `docs`-directory, Altinnpedia
or a separate linked PR in
[altinn-studio-docs.](https://github.com/Altinn/altinn-studio-docs), if
applicable)

---------

Co-authored-by: Magnus Sandgren <5285192+MagnusSandgren@users.noreply.github.com>

src/Digdir.Library.Utils.AspNet/AspNetUtilitiesExtensions.cs

@@ -15,6 +15,8 @@ namespace Digdir.Library.Utils.AspNet;
 
 public static class AspNetUtilitiesExtensions
 {
+    private const string MassTransitSource = "MassTransit";
+
     public static IServiceCollection AddAspNetHealthChecks(this IServiceCollection services, Action<AspNetUtilitiesSettings, IServiceProvider>? configure = null)
     {
         var optionsBuilder = services.AddOptions<AspNetUtilitiesSettings>();
@@ -67,6 +69,7 @@ public static WebApplicationBuilder ConfigureTelemetry(this WebApplicationBuilde
 
                 tracing.AddHttpClientInstrumentation();
                 tracing.AddNpgsql();
+                tracing.AddSource(MassTransitSource); // MassTransit ActivitySource
             })
             .WithMetrics(metrics =>
             {