[Part1] Support Activity Status and status description in Zipkin Exporter.

[Yun-Ting]

Fixes parts of #2569.

Added support for Activity.Status/Description in ZipkinExporter.
System.Diagnostic.DiagnosticSource version 6.0.0 introduced native support for storing status/description in the Activity itself.

This PR modified the exporter to retrieve status from the newly added fields if it was set.
To maintain backward compatibility, the control flow would fell back to retrieve status from the activityTags if the native status/description were not set.

Background : Please review Console.Exporter where the same logic were exercised: #3061.

Next items : Add similar support for OTLP/Jaeger Exporters.

For significant contributions please make sure you have completed the following items:

• Appropriate CHANGELOG.md updated for non-trivial changes
• Design discussion issue #
• Changes in public API reviewed

[codecov]

Codecov Report

Merging #3003 (ac081d7) into main (bdcf942) will increase coverage by 0.03%.
The diff coverage is 100.00%.

❗ Current head ac081d7 differs from pull request most recent head 578d445. Consider uploading reports for the commit 578d445 to get more accurate results

@@            Coverage Diff             @@
##             main    #3003      +/-   ##
==========================================
+ Coverage   84.71%   84.75%   +0.03%     
==========================================
  Files         259      259              
  Lines        9121     9142      +21     
==========================================
+ Hits         7727     7748      +21     
  Misses       1394     1394              

Impacted Files	Coverage Δ
...plementation/ZipkinActivityConversionExtensions.cs	99.12% <100.00%> (+0.19%)	⬆️