Workaround for https://github.com/dotnet/arcade/issues/7371

[MattGal]

Have azure-pipelines reporter parse XML for failures if ADO fails for any reason, return 0 if we actually passed until the Helix Client does this itself.

To double check:

• The right tests are in and and the right validation has happened. Guidance: https://github.com/dotnet/core-eng/tree/master/Documentation/Validation

Since this is a weird error-case from an API we don't have a way to mock, I created this run where every worker in the Azure-DevOps reporter crashes. Note in that run the non-XUnit results were expected to and did fail because I didn't check for them; this is just to mitigate the main stream scenario of XUnit results. If we need to keep this workaround for a longer time can implement that.

Helix Log

Reporting has failed.  Running mitigation for https://github.com/dotnet/arcade/issues/7371
Searching 'C:\h\w\A8DD094C\w\B173094F\e' for test results files
Found results file C:\h\w\A8DD094C\w\B173094F\e\testResults.xml 
Searching 'C:\h\w\A8DD094C\w\B173094F\uploads' for test results files
Reporter script has failed, but we were able to find XUnit test results with no failures.

[agocke]

LGTM