Add OTEL tracing support for Wiremock + automatic OTEL for Aspire integration (#1418)

* Update aspire to 13.1 (examples + code)

Allows usage of aspire CLI which is very useful for dev in codespaces (for my next PR).

* Add OTEL support

* Initial PR feedback

* PR feedback

* PR feedback

* PR feedback

* Cleanup.

* Cleanup

* Fix

* Fix

* Rename stuff around to be more accurate

* PR feedback

* Update WireMock.Net.OpenTelemetry.csproj

Update <Authors>

* PR feedback parser

* PR feedback package versions

* Status code feedback.

* Update preprocessor directives to to Activity Tracing instead of OpenTelemetry. Is more descriptive.

* Add tests

* Improve tests

---------

Co-authored-by: Stef Heyenrath <Stef.Heyenrath@gmail.com>

src/WireMock.Net.Minimal/WireMock.Net.Minimal.csproj

@@ -52,6 +52,11 @@
         <DefineConstants>$(DefineConstants);TRAILINGHEADERS</DefineConstants>
     </PropertyGroup>
 
+    <!-- Enable Activity tracing support for .NET 5+ where ActivitySource is available -->
+    <PropertyGroup Condition="'$(TargetFramework)' == 'net5.0' or '$(TargetFramework)' == 'net6.0' or '$(TargetFramework)' == 'net7.0' or '$(TargetFramework)' == 'net8.0'">
+        <DefineConstants>$(DefineConstants);ACTIVITY_TRACING_SUPPORTED</DefineConstants>
+    </PropertyGroup>
+
     <ItemGroup>
       <Compile Remove="Matchers\LinqMatcher.cs" />
     </ItemGroup>