[System.Diagnostics.DiagnosticSource] Support listening to meters out-of-proc using a wildcard

[CodeBlanch]

Changes

• Adds support inside MetricsEventSource for listening to meters out-of-proc by using a wildcard\prefix style (ex: *, Company.Library*) for meter name in spec

/cc @noahfalk @samsp-msft @tarekgh @rajkumar-rangaraj

[tarekgh]

/azp run runtime-libraries-coreclr outerloop

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Azure Pipelines successfully started running 1 pipeline(s).

[tarekgh]

@ericstj this fix is needed for enabling scenarios of dotnet-monitor with OpenTelemetry. Please let us know if you have any feedback or we good to go.

@noahfalk please have a look it is one line fix.

[CodeBlanch]

@tarekgh I added support for doing a prefix as well as the blanket wildcard. Thinking more about this, that will probably be very useful for users who may want to do things like listen to all runtime or aspnetcore metrics but may not care about other things so much.

Also had to fix up the tests a bit for introduction of runtime metrics. And there was a cast issue seems to have been introduced recently 🤷

[tarekgh]

This is not worth the ifdef you can write it like

spec.MeterName.Length > 0 && spec.MeterName[spec.MeterName.Length - 1] == '*'

Or just use spec.MeterName.EndsWith("*", StringComparison.Ordinal)) which still fast enough even in .NET 8.0.

[CodeBlanch]

Updated! I also made all the string comparisons StringComparison.OrdinalIgnoreCase. My thinking there is these values are likely coming from config so it is nice to make them as forgiving as possible 😄